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1.
Mil Med ; 184(7-8): e212-e217, 2019 07 01.
Article in English | MEDLINE | ID: mdl-30690453

ABSTRACT

INTRODUCTION: With the removal in 2016 of restrictions on recruiting women to the combat arms in the all-volunteer Australian Army, a key question has been whether adding women to small combat teams will reduce the sense of cohesion among their members, which entails their subjective bonds with each other, their leader, and wider organization. Despite recent initiatives in Australia and the USA, there are too few women in combat units in any country to answer this question and how these subjective bonds affect a team's ability to stick together under pressure.Men and women recruits in the Australian Army have undertaken basic soldier training in mixed-gender teams since 1995. Recruit training provides the foundation of teamwork and cohesion in all types of units. The present study capitalized on this well-established practice as an avenue for illuminating the development of cohesion in the form of subjective bonds within mixed-gender teams. MATERIALS AND METHODS: The respondents were 89 females and 434 males, who were members of 46 teams denoted as "sections," each consisting of 9-12 recruits. The gender mix of the sections varied from 0% female (all males) up to 55.6% females. The recruits were surveyed on three occasions during the 81-day recruit training (Days 10, 46, 80). The questionnaire comprised 18 items asking the recruits' ratings of "vertical" bonding with their instructor/leaders, "horizontal" bonding within their sections, and "organizational" bonding with the wider Australian Army. This study was conducted under Defence ethics approval DPR-LREP 069-15. RESULTS: At the start of training, vertical bonding of the recruits with their instructor/leaders was significantly higher than horizontal and organizational bonding, which were similar. During training, all three types of bonding as rated by both female and male recruits increased and largely converged to a high level. Any apparent gender-related differences were not statistically significant.Bonding scores for females did decline slightly as the proportion of women increased, but only significantly for vertical bonding. Even these declines all occurred within a band of high scores. For male recruits, there was no discernible relationship of bonding scores with the percentage of females in a section; the lines of best fit appeared flat. CONCLUSIONS: Within the Australian Army, women and men have been trained in mixed-gender sections since 1995 with sustained success, at least anecdotally. The present findings provide the first independent confirmation that all three dimensions of cohesion increase in strength during recruit training much to the same degree in women and men alike. To the extent that felt cohesion translates into effective teamwork, mixed-gender training establishes a sound foundation for integrating women into combat units as well as support units, where they have traditionally served.


Subject(s)
Cooperative Behavior , Students/psychology , Adult , Australia , Female , Humans , Male , Military Personnel/statistics & numerical data , Sex Factors , Students/statistics & numerical data , Surveys and Questionnaires
2.
Mil Med ; 184(5-6): e131-e136, 2019 05 01.
Article in English | MEDLINE | ID: mdl-30395263

ABSTRACT

INTRODUCTION: In integrating women into combat roles, one key question has been whether women will reduce the cohesion of small teams, which is their ability to stick together and perform well under pressure. Among other things, team cohesion protects the mental health of military personnel during initial training as well in operational zones. To provide new converging evidence on the cohesion of all-male versus mixed-gender recruit teams at the end of training, cohesion ratings were obtained from both recruits and their instructors. MATERIALS AND METHODS: The recruits consisted of 83 females, 398 males, and 8 non-specified individuals across 46 small teams. The teams' gender mix varied from 0% female (all males) up to 64% female. The recruit questionnaire comprised 18 items that covered the bonding of the recruits with each other (horizontal), with their instructor leaders (vertical), and with the wider Army (organizational). In addition, two to three instructors rated each team on their horizontal and vertical bonding. This study had Defence ethics approval (DPR-LREP 069-15). RESULTS: (1). The ratings of recruits and instructors were significantly correlated for both horizontal bonding (r = 0.44) and vertical bonding (r = 0.49). These correlations were similar to correlations obtained previously from U.S. Army infantry platoons. (2). The recruits in the present study gave their teams significantly higher ratings for horizontal bonding (M = 4.18, SD =0.33) than did their instructors (M = 3.95, SD =0.31), F(1,45) = 22.12, p < 0.001). Neither the ratings of recruits nor their instructors were significantly correlated with the percentage of females per team, rs = 0.063, 0.249, ps > 0.05. (3). For vertical bonding, the recruits' ratings (M = 4.48, SD =0.37) were high and similar to those of instructors (M = 4.56, SD =0.44), F(1,45) = 1.65, p > 0.20). The vertical bonding scores were also not significantly correlated with the percentage of females per team, rs = -0.168, -0.139, ps > 0.25. CONCLUSIONS: Our findings agree with a previously published analysis of recruit performance over a 5-year period (2011-2015). Composite instructor ratings of recruit performance, including their teamwork, were similar for males and females regardless of the gender composition of platoons, which ranged from all male to 45% female.The next step in this research is to determine the pattern and dynamics of bonding between team members and their leaders as soldiers progress through their advanced training and ultimately operational deployment. Such research should reveal whether any differences in cohesion appear in relation to team gender composition.The present results have useful implications for health professionals. When discussing feelings of stress, depression, and/or with male or female military clients, health professionals may find it worthwhile to explore their clients' sense of bonding with their team members, their leaders, and their wider organization as one possible contributor to the individual's concern. By the same token, advice aimed at promoting the three dimensions of cohesion may help capitalize on their protective effects.


Subject(s)
Faculty/psychology , Interpersonal Relations , Military Personnel/psychology , Patient Care Team/standards , Adaptation, Psychological , Adult , Faculty/statistics & numerical data , Female , Humans , Male , Military Personnel/education , Military Personnel/statistics & numerical data , Patient Care Team/statistics & numerical data
3.
Mil Med ; 184(5-6): e147-e153, 2019 05 01.
Article in English | MEDLINE | ID: mdl-30252088

ABSTRACT

INTRODUCTION: Armed forces view their officers' character as foundational to their ability to lead the personnel entrusted to them. The character of junior officers is of particular interest, because they must increasingly make quick, morally-laden decisions while dispersed among civilians without time to consult their commanders. However, little is systematically known about the character of officers. Accordingly, the present study was aimed at mapping Australian Army junior officers' perceptions of the chief aspects of their own character and also those of their main role models, specifically, their senior officers, including their trustworthiness as an essential aspect of effective leadership. The present study also tested whether these character perceptions were aligned with four core values of the Australian Army - courage, initiative, teamwork, and respect - which are intended to shape the character of its personnel. MATERIALS AND METHODS: The respondents (N = 171 lieutenants) ranked how well each of 24 positive character strengths applied to themselves as individuals. To test the alignment of these rankings with the respondents' perception of their leaders' character, respondents nominated the five top strengths of their effective leaders. This study was approved by the Australian Defence Human Research Ethics Committee (ADHREC 009-2013). RESULTS: With regard to the first aim, five character strengths - integrity, leadership, good judgment, trustworthy, and teamworker - were ranked by the respondents as being their chief personal strengths at frequencies significantly above those expected from random allocation.With regard to the second aim, the respondents aligned the rankings of their character strengths with those of their effective leaders through the entire list, not just the highest-ranking items. Nevertheless, there were two significant differences. The respondents assigned their leaders higher ranks for wisdom than for themselves, but assigned lower ranks to their leaders for being trustworthy.With regard to the third aim, the respondents' perceptions of their chief character strengths were not well aligned with the four core values of the Australian Army. Teamworker was given a significant top ranking, but courage, initiative, and respectful were not. Thus, the respondents did not appear to respond according to organizational demand characteristics. CONCLUSIONS: The present study achieved its aims. First, it revealed five character strengths that junior officers in the Australian Army tended to see as their own chief strengths. Second, the junior officers saw their character strengths as aligned with those of their senior officers. By and large, this alignment extended across all the character strengths, regardless of their specific ranking. Subject to further experimental testing, this finding provides correlational evidence that junior officers may model their character on what they see in their senior officers. Third, in contrast, the junior officers' rankings were not well aligned with the Australian Army's stated core values. The junior officers saw teamworker as one of their chief strengths, but not courage, initiative, or respectful. This pattern does not imply that the junior officers rejected strengths as valuable but only that they are not among the junior officers' own chief strengths.


Subject(s)
Character , Military Personnel/psychology , Australia , Chi-Square Distribution , Female , Humans , Leadership , Male , Military Personnel/statistics & numerical data , Surveys and Questionnaires , Young Adult
4.
Accid Anal Prev ; 119: 1-15, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29966858

ABSTRACT

There is growing interest in young driver training that addresses age-related factors, including incompletely developed impulse control. Two studies investigated whether training of response inhibition can reduce risky simulated driving in young drivers (aged 16-24 years). Each study manipulated aspects of response inhibition training then assessed transfer of training using simulated driving measures including speeding, risky passing, and compliance with traffic controls. Study 1 (n = 65) used a Go/No-go task, Stop Signal Task and a Collision Detection Task. Designed to promote engagement, learning, and transfer, training tasks were driving-relevant and adaptive (i.e. difficulty increased as performance improved), included performance feedback, and were distributed over five days. Control participants completed matching "filler" tasks. Performance on trained tasks improved with training, but there was no significant improvement in simulated driving. Study 2 enhanced response inhibition training using Go/No-go and SST tasks, with clearer performance feedback, and 10 days of training. Control participants completed testing only, in order to avoid any possibility of training response inhibition in the filler tasks. Again performance on trained tasks improved, but there was no evidence of transfer of training to simulated driving. These findings suggest that although training of sufficient interest and duration can improve response inhibition task performance, a training schedule that is likely to be acceptable to the public does not result in improvements in simulated driving. Further research is needed to investigate whether response inhibition training can improve risky driving in the context of real-world motivations for risky driving.


Subject(s)
Accidents, Traffic/prevention & control , Automobile Driving/education , Impulsive Behavior , Inhibition, Psychological , Risk-Taking , Adolescent , Adult , Age Factors , Computer Simulation , Female , Humans , Male , Motivation , Risk , Task Performance and Analysis , Young Adult
5.
Mil Med ; 183(5-6): e147-e152, 2018 05 01.
Article in English | MEDLINE | ID: mdl-29425352

ABSTRACT

Introduction: Although men and women recruits to the Australian Army have trained in mixed-gender platoons since 1995, restrictions on women joining the combat arms were only removed in 2016. As part of a longitudinal study starting with recruit training, this article examined recruit records collected before 2016 with the aims of delineating (1) the relative performance of women versus men in mixed-gender platoons and (2) the relative performance of men in mixed-gender platoons versus all-male platoons. Materials and Methods: De-identified instructor ratings for 630 females and 4,505 males who completed training between 2011 and 2015 were obtained. Recruits were distributed across 128 platoons (averaging 41.6 members, SD = 8.3) of which 75% contained females, in proportions from 5% to 45%. These analyses were conducted under defense ethics approval DPR-LREP 069-15. Results: Factor analyses revealed that instructor ratings generally loaded onto a single factor, accounting 77.2% of the variance. Consequently, a composite recruit performance score (range 1-5) was computed for 16 of 19 competencies. Analyses of the scores revealed that the distributions of the scores for females and males overlapped considerably. Observed effects were negligible to small in size. The distributions were all centered between 3.0 and 3.5. In mixed-gender platoons, 51% of the females and 52% of the males fell in this band, and 44% of recruits in all-male platoons had scores in this band. The lower three bands (1.0-3.0) contained a slightly greater proportion of females (18%) than males in either mixed-gender platoons (12%) or all-male platoons (12%). Conversely, the upper three bands (3.5-5.0) contained a slightly smaller percentage of females (31%) than males in either mixed-gender platoons (36%) or all-male platoons (44%). Although scores for females were reliably lower than those of males in mixed-gender platoons, χ2 (4) = 16.01, p < 0.01, the effect size (V = 0.07) did not reach the criterion for even a small effect (0.10). For male recruits, those in mixed-gender platoons had scores that were reliably lower than in all-male platoons, χ2 (4) = 48.38, p < 0.001; its effect size (V = 0.11) just exceeded the criterion for a small effect (0.10). Further analyses revealed that male scores had a near-zero correlation (r = -0.033) with the proportion of females in platoons (0-45%). Conclusion: This large-scale secondary analysis of instructor ratings of female and male recruits provides a platform for monitoring the integration of women into the combat arms. The analyses revealed nearly complete overlap in the performance of female versus male recruits. The detected gender-related differences were negligible to small in size. These small differences must be viewed with considerable caution. They may be artifacts of rater bias or other uncontrolled features of the rating system, which was designed for reporting individual recruit performance rather than aggregate analyses. Even with these limitations, this baseline snapshot of recruit performance suggests that, at recruit training, women and men are already working well together, which bodes well for their subsequent integration into the combat arms.


Subject(s)
Military Personnel/statistics & numerical data , Personnel Selection/statistics & numerical data , Sex Factors , Adult , Australia , Female , Humans , Longitudinal Studies , Male , Military Personnel/education , Military Personnel/psychology , Personnel Selection/standards , Students/statistics & numerical data , Teaching/psychology , Teaching/statistics & numerical data , Work Performance/statistics & numerical data
6.
Accid Anal Prev ; 103: 37-43, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28384487

ABSTRACT

The risky driving of young drivers may owe in part to youthful motivations (such as experience-seeking, authority rebellion, desire for peer approval) combined with incompletely developed impulse control. Although self-reported impulsiveness has been positively associated with self-reports of risky driving, results based on objective measures of response inhibition (e.g., Go/No-go tasks) have been inconclusive. The present study examined interrelationships between measures of response inhibition, self-report impulsiveness scales, and responses to events during a simulated drive that were designed to detect impulsive, unsafe behaviours (e.g., turning across on-coming traffic). Participants were 72 first-year Psychology students. More speeding and "Unsafe" responding to critical events during simulated driving were associated with poorer impulse control as assessed by commission errors during a Go/No-Go task. These results consolidate evidence for a relationship between impulse control and risky driving amongst young drivers.


Subject(s)
Automobile Driving/psychology , Impulsive Behavior , Risk-Taking , Accidents, Traffic/psychology , Adolescent , Adult , Female , Humans , Male , Risk , Self Report , Young Adult
7.
Mil Med ; 181(9): 996-1001, 2016 09.
Article in English | MEDLINE | ID: mdl-27612343

ABSTRACT

Civilian employees, contractors, and private community clinicians are increasingly providing health treatment to currently serving and former military personnel. This study addresses recent calls for evidence-based information to assist civilian practitioners in understanding the perspectives of their military clients. To this end, the self-reported character strengths of military personnel were elicited as an operationalized expression of their underlying personal values that shape their perspectives and conduct as soldiers. Specifically, Australian Army Special Forces operators and support personnel (N = 337) were asked to rank themselves on 24 character strengths. The three character strengths of integrity, teamworker, and good judgment were ranked significantly above random assignment. Nearly all the respondents (84%) gave a top rank to at least one of these character strengths. Differences between the operators and support personnel were modest. Results are discussed with respect to establishing an effective relationship between military clients and civilian health care practitioners.


Subject(s)
Character , Military Personnel/psychology , Self Report , Adult , Australia , Female , Humans , Male , Problem Solving , Professional Autonomy , Social Skills , Surveys and Questionnaires
8.
Mil Med ; 180(8): 857-62, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26226527

ABSTRACT

Australian Army Special Forces (SF) applicants (N = 95) were asked to rank themselves on 24 character strengths at the start of the selection process. Across all applicants, the character strength of integrity was most frequently assigned a top-four rank (45%), followed by team worker (41%), persistence (36%), and love of learning (25%). Successful applicants assigned a top-four rank to team worker significantly more often than unsuccessful applicants (65% versus 32%). The likelihood of passing when team worker was highly ranked (37.5%) was 2.6 times greater than without team worker listed in the top ranks (14.3%). Self-ratings of hardiness revealed no discernible differences between successful and unsuccessful applicants, either alone or in combination with the team worker rankings. These results were largely consistent with the results of a previous study with a cohort of applicants for a different Australian SF unit. Results are discussed with respect to their implications for enhancing the assessment of SF applicants.


Subject(s)
Achievement , Career Choice , Military Personnel/psychology , Personality Assessment , Resilience, Psychological , Adult , Australia , Female , Humans , Male , Surveys and Questionnaires , Young Adult
9.
Mil Med ; 180(2): 151-7, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25643382

ABSTRACT

For entry into the Australian Army Special Forces (SF), applicants undergo a barrage of strenuous physical and psychological assessments. Despite this screening, subsequent attrition rates in the first weeks of initial selection courses are typically high, and entry testing results have had limited success for predicting who will complete these courses. An SF applicant's character is often thought to be a decisive factor; however, this claim has remained untested. Accordingly, SF applicants (N = 115) were asked to rank themselves on 24 character strengths at the start of the selection process. Successful applicants (n =18) assigned their top ranks to team worker (72%), integrity (67%), and persistence (50%). Applicants (n = 31) who did not include any of those three strengths in their top ranks all failed to complete the selection process. In contrast, successful versus unsuccessful applicants did not discernibly differ on physical assessments and a written test. Results are discussed with respect to their implications for enhancing the assessment of SF applicants.


Subject(s)
Military Personnel/psychology , Personality Assessment , Personnel Selection/methods , Adult , Australia/epidemiology , Humans , Male , Military Personnel/statistics & numerical data , Prospective Studies
10.
Learn Mem ; 21(11): 585-90, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25320350

ABSTRACT

The present experiment tested whether or not the time course of a conditioned eyeblink response, particularly its duration, would expand and contract, as the magnitude of the conditioned response (CR) changed massively during acquisition, extinction, and reacquisition. The CR duration remained largely constant throughout the experiment, while CR onset and peak time occurred slightly later during extinction. The results suggest that computational models can account for these results by using two layers of plasticity conforming to the sequence of synapses in the cerebellar pathways that mediate eyeblink conditioning.


Subject(s)
Blinking , Conditioning, Eyelid/physiology , Extinction, Psychological/physiology , Learning/physiology , Nictitating Membrane/physiology , Animals , Motor Activity , Rabbits , Time Factors
11.
Mil Med ; 179(4): 404-12, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24690965

ABSTRACT

This study tested whether cognitive hardiness moderates the adverse effects of deployment-related stressors on health and well-being of soldiers on short-tour (4-7 months), peacekeeping operations. Australian Army reservists (N = 448) were surveyed at the start, end, and up to 24 months after serving as peacekeepers in Timor-Leste or the Solomon Islands. They retained sound mental health throughout (Kessler 10, Post-Traumatic Checklist-Civilian, Depression Anxiety Stress Scale 42). Ratings of either traumatic or nontraumatic stress were low. Despite range restrictions, scores on the Cognitive Hardiness Scale moderated the relationship between deployment stressors and a composite measure of psychological distress. Scatterplots revealed an asymmetric pattern for hardiness scores and measures of psychological distress. When hardiness scores were low, psychological distress scores were widely dispersed. However, when hardiness scores were higher, psychological distress scores became concentrated at a uniformly low level.


Subject(s)
Mental Health , Military Personnel/psychology , Personal Satisfaction , Resilience, Psychological , Stress Disorders, Post-Traumatic/psychology , Adolescent , Adult , Australia/epidemiology , Female , Follow-Up Studies , Humans , Incidence , Male , Retrospective Studies , Stress Disorders, Post-Traumatic/epidemiology , Young Adult
12.
Mil Med ; 179(2): 137-42, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24491608

ABSTRACT

In postconflict zones, both aid and military personnel face chronic stress, including boredom, isolation, family separation, and difficult living conditions, plus the intra-organizational and interpersonal frictions found in all work settings. Australian Army reservists (N = 350) were surveyed during and after peacekeeping in the Solomon Islands. Most respondents reported having a positive experience (66%) and fewer reported their experience was neutral (16%) or negative (17%). The stressors reported by reservists predominately emanated from work-related sources rather than from separation or the operational environment. The discussion considers leadership factors, especially the role of organizational justice in deployed organizations, that may influence the deployment experience.


Subject(s)
Military Personnel/psychology , Stress, Psychological/etiology , Adolescent , Adult , Australia , Boredom , Humans , Interpersonal Relations , Male , Middle Aged , Social Isolation , Workplace/psychology , Young Adult
13.
Learn Mem ; 20(2): 97-102, 2013 Jan 16.
Article in English | MEDLINE | ID: mdl-23325726

ABSTRACT

Rabbits were classically conditioned using compounds of tone and light conditioned stimuli (CSs) presented with either simultaneous onsets (Experiment 1) or serial onsets (Experiment 2) in a delay conditioning paradigm. Training with the simultaneous compound reduced the likelihood of a conditioned response (CR) to the individual CSs ("mutual overshadowing") but left CR timing unaltered. CR peaks were consistently clustered around the time of unconditioned stimulus (US) delivery. Training with the serial compound (CSA→CSB→US) reduced responding to CSB ("temporal primacy/information effect") but this effect was prevented by prior CSB→US pairings. In both cases, serial compound training altered CR timing. On CSA→CSB test trials, the CRs were accelerated; the CR peaks occurred after CSB onset but well before the time of US delivery. Conversely, CRs on CSB- trials were decelerated; the distribution of CR peaks was variable but centered well after the US. Timing on CSB- trials was at most only slightly accelerated. The results are discussed with respect to processes of generalization and spectral timing applicable to the cerebellar and forebrain pathways in eyeblink preparations.


Subject(s)
Association Learning/physiology , Conditioning, Classical/physiology , Cues , Nictitating Membrane/physiology , Acoustic Stimulation , Animals , Rabbits , Reaction Time/physiology , Time Factors
14.
Learn Behav ; 40(3): 305-19, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22927003

ABSTRACT

The temporal-difference (TD) algorithm from reinforcement learning provides a simple method for incrementally learning predictions of upcoming events. Applied to classical conditioning, TD models suppose that animals learn a real-time prediction of the unconditioned stimulus (US) on the basis of all available conditioned stimuli (CSs). In the TD model, similar to other error-correction models, learning is driven by prediction errors--the difference between the change in US prediction and the actual US. With the TD model, however, learning occurs continuously from moment to moment and is not artificially constrained to occur in trials. Accordingly, a key feature of any TD model is the assumption about the representation of a CS on a moment-to-moment basis. Here, we evaluate the performance of the TD model with a heretofore unexplored range of classical conditioning tasks. To do so, we consider three stimulus representations that vary in their degree of temporal generalization and evaluate how the representation influences the performance of the TD model on these conditioning tasks.


Subject(s)
Conditioning, Classical , Models, Psychological , Algorithms , Animals , Association Learning , Computer Simulation/statistics & numerical data , Reinforcement, Psychology , Time Factors
15.
Accid Anal Prev ; 43(3): 932-8, 2011 May.
Article in English | MEDLINE | ID: mdl-21376885

ABSTRACT

Two methods of metacognitive reflection for promoting compliance with an aviation safety rule were tested in a transfer design. Two groups of pilots (n = 10) conducted a simulated flight entailing a search for a target on the ground. During this flight, only 35% of the pilots stayed above an altitude of 500 ft, the minimum allowed by relevant regulations. Following the flight, one group completed a self-explanation questionnaire, in which they explained their actions during the initial flight and what they would do in future flights. The other group completed a relapse-prevention questionnaire, in which they identified the circumstances leading to safety lapses and their future avoidance. A third group (n = 10) formed a rest control; they conducted a familiarization flight without a ground target or debriefing. One week later, all pilots conducted a series of test flights with the same or different ground targets as the initial flight. The self-explanation group showed 100% compliance when the ground target remained the same, but less so (<70%) when the ground target was different. The relapse-prevention group and control groups both showed low levels of compliance across all test flights (<30%). The results are discussed from theoretical and applied perspectives.


Subject(s)
Accidents, Aviation/legislation & jurisprudence , Accidents, Aviation/prevention & control , Aviation/education , Comprehension , Computer Simulation , Dangerous Behavior , Environment Design , Retention, Psychology , Safety/legislation & jurisprudence , Transfer, Psychology , Adolescent , Adult , Altitude , Cooperative Behavior , Female , Follow-Up Studies , Generalization, Response , Humans , Male , Risk-Taking , Young Adult
16.
Accid Anal Prev ; 43(3): 991-7, 2011 May.
Article in English | MEDLINE | ID: mdl-21376892

ABSTRACT

Accidents and incidents often occur, because a basic and seemingly simple rule is 'forgotten', either unintentionally (error, lapse) or with some degree of deliberate negligence (violation). The present experiment examined the utility of a rehearsal and a last-minute reminder in reducing the magnitude of deviations from an important safety rule by qualified, but relatively inexperienced pilots, specifically, remaining above an altitude of 500-ft. A single rehearsal flight entailing a search for a target on the ground increased the minimum altitude in later flights, but this positive effect did not completely generalize when the target on the ground was changed. These results suggest that the rehearsal flight was encoded in a context-specific manner. The addition of an explicit, last minute reminder about the mandated minimum altitude just before each test flight failed to significantly alter the pilots' behavior. The results are discussed with respect to their theoretical and practical implications.


Subject(s)
Accidents, Aviation/prevention & control , Accidents, Aviation/psychology , Aviation/education , Cooperative Behavior , Practice, Psychological , Reinforcement, Verbal , Safety , Adolescent , Adult , Altitude , Generalization, Psychological , Humans , Male , New South Wales , Risk-Taking , Transfer, Psychology , Young Adult
17.
Learn Mem ; 17(12): 600-4, 2010 Dec.
Article in English | MEDLINE | ID: mdl-21075900

ABSTRACT

Using interstimulus intervals (ISIs) of 125, 250, and 500 msec in trace conditioning of the rabbit nictitating membrane response, the offset times and durations of conditioned responses (CRs) were collected along with onset and peak latencies. All measures were proportional to the ISI, but only onset and peak latencies conformed to the criterion for scalar timing. Regarding the CR's possible protective overlap of the unconditioned stimulus (US), CR duration increased with ISI, while the peak's alignment with the US declined. Implications for models of timing and CR adaptiveness are discussed.


Subject(s)
Conditioning, Classical/physiology , Conditioning, Eyelid/physiology , Nictitating Membrane/physiology , Acoustic Stimulation , Animals , Rabbits , Time Factors
18.
Behav Neurosci ; 123(5): 1095-101, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19824776

ABSTRACT

The present experiment characterized conditioned nictitating membrane (NM) movements as a function of CS duration, using the full range of discernible movements (>.06 mm) rather than movements exceeding a conventional criterion (>.50 mm). The CS-US interval was fixed at 500 ms, while across groups, the duration of the CS was 50 ms (trace), 550 ms (delay), or 1050 ms (extended delay). The delay group showed the highest level of acquisition. When tested with the different CS durations, the delay and extended delay groups showed large reductions in their responses when their CS was shortened to 50 ms, but the trace group maintained its response at all durations. Timing of the conditioned movements appeared similar across all manipulations. The results suggest that the CS has both a fine timing function tied to CS onset and a general predictive function tied to CS duration, both of which may be mediated by cerebellar pathways.


Subject(s)
Conditioning, Eyelid/physiology , Nictitating Membrane/physiology , Reaction Time/physiology , Acoustic Stimulation , Animals , Auditory Perception/physiology , Electric Stimulation , Female , Rabbits
19.
Behav Neurosci ; 123(1): 212-7, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19170446

ABSTRACT

The present experiment was aimed at characterizing the timing of conditioned nictitating membrane (NM) movements as function of the interstimulus interval (ISI) in delay conditioning for rabbits (Oryctolagus cuniculus). Onset latency and peak latency were approximately, but not strictly, scalar for all but the smallest movements (<.10 mm). That is, both the mean and standard deviation of the timing measures increased in proportion to the ISI, but their coefficients of variation (standard deviation/mean) tended to be larger for shorter ISIs. For all ISIs, the absolute timing of the NM movements covaried with magnitude. The smaller movements (approximately, .11-.50 mm) were highly variable, and their peaks tended to occur well after the time of US delivery. The larger movements (>.50 mm) were less variable, and their peaks were better aligned with the time of US delivery. These results are discussed with respect to their implications for current models of timing in eyeblink conditioning.


Subject(s)
Conditioning, Eyelid/physiology , Nictitating Membrane/physiology , Reaction Time/physiology , Acoustic Stimulation/methods , Animals , Female , Psychoacoustics , Rabbits , Time Factors
20.
Neural Comput ; 20(12): 3034-54, 2008 Dec.
Article in English | MEDLINE | ID: mdl-18624657

ABSTRACT

The phasic firing of dopamine neurons has been theorized to encode a reward-prediction error as formalized by the temporal-difference (TD) algorithm in reinforcement learning. Most TD models of dopamine have assumed a stimulus representation, known as the complete serial compound, in which each moment in a trial is distinctly represented. We introduce a more realistic temporal stimulus representation for the TD model. In our model, all external stimuli, including rewards, spawn a series of internal microstimuli, which grow weaker and more diffuse over time. These microstimuli are used by the TD learning algorithm to generate predictions of future reward. This new stimulus representation injects temporal generalization into the TD model and enhances correspondence between model and data in several experiments, including those when rewards are omitted or received early. This improved fit mostly derives from the absence of large negative errors in the new model, suggesting that dopamine alone can encode the full range of TD errors in these situations.


Subject(s)
Dopamine/metabolism , Models, Neurological , Neurons/physiology , Reaction Time/physiology , Reward , Action Potentials/physiology , Algorithms , Animals , Cues , Humans , Time Factors
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