The effect of nitric oxide synthase inhibition on cognitive ability and strategies employed for place learning in the water maze: sex differences.

Male and female rats use different cognitive strategies in the solution of place-learning problems in the water maze despite similar abilities. The female-type strategy has been negatively correlated with cortical nitric oxide (NO) metabolites. The present study aimed to examine the effect of NO synthase (NOS) inhibition (N(omega)-nitro-L-arginine, L-NA) on cognitive ability and strategy in the water maze, and to evaluate possible sex differences. In a 2 (male versus female) x2 (L-NA versus saline) factorial design, rats were trained to find the platform (visible or hidden), always in the same position, for 12 days. L-NA impaired acquisition, during the earlier phases and more prominently in females. This impairment was quite dramatic and unique to females during the first day that the platform was hidden following 3 days of visible-platform conditions. After acquisition, the visible platform's position was shifted, thereby presenting the rats with a choice (searching for the hidden platform in the previous location, i.e. adopting a conceptual cognitive style, or escaping to the visible platform in a new position, i.e. adopting a perceptual style). On the first of the four shift trials (where the newly positioned platform was proximal to the rat's starting position), female rats showed the previously found tendency to adopt a perceptual style escape directly in clear contrast to saline-treated males. The L-NA-treated males tended to manifest female-like perceptual style, suggesting that inhibition of NO synthesis in males weakened the tendency to choose a conceptual style in this shifted-platform task. The role of NO in both cognitive and non-cognitive psychological functions is discussed.

The color-vision approach to emotional space: cortical evoked potential data.

A framework for accounting for emotional phenomena proposed by Sokolov and Boucsein (2000) employs conceptual dimensions that parallel those of hue, brightness, and saturation in color vision. The approach that employs the concepts of emotional quality. intensity, and saturation has been supported by psychophysical emotional scaling data gathered from a few trained observers. We report cortical evoked potential data obtained during the change between different emotions expressed in schematic faces. Twenty-five subjects (13 male, 12 female) were presented with a positive, a negative, and a neutral computer-generated face with random interstimulus intervals in a within-subjects design, together with four meaningful and four meaningless control stimuli made up from the same elements. Frontal, central, parietal, and temporal ERPs were recorded from each hemisphere. Statistically significant outcomes in the P300 and N200 range support the potential fruitfulness of the proposed color-vision-model-based approach to human emotional space.

An epistemologically arrogant community of contending scholars: a pre-Socratic perspective on the past, present, and future of the Pavlovian Society.

UNLABELLED: The paper begins with a statement of the Society's purpose and its pre-Socratic roots. The Society differs from other contemporary scientific and scientific-professional societies in that it is thoroughly apolitical, unusually open to discussion and debate, and has had a restricted scholarly written impact. I then suggest and interpret six phases in the Society's history: (1) the pre-Socratic roots; (2) Pavlov and the young Gantt; (3) the Society's Gantt score of years; (4) the Joe McGuigan decade; (5) the Stewart Wolf era; (6) reforming the Society. I conclude with the hope that even if the content of the Society's interests changes, it will preserve the pre-Socratic approach against the various forms of intellectual barbarism that continue to arise. KEYWORDS: Pre-Socratics, disinterested discussion, conflict of ideas, contending scholars, Pavlovian procedures

Revisiting the learning-without-awareness question in human Pavlovian autonomic conditioning: focus on extinction in a dichotic listening paradigm.

Numerous studies have indicated that, consistent with current "cognitive" accounts of information processing, human Pavlovian autonomic discrimination acquisition cannot occur without awareness of the CS-US relationship. However, extinction studies have suggested that awareness is not necessary, findings that, in information-processing terms, have been explained by assuming that the processing by the extinction stage is parallel (automatic) rather than serial (controlled). This explanation was tested in an 80-subject study. The first, acquisition phase was a standard semantic differential conditioning arrangement with a 96-db white noise as US, and a "long" CS-US interval of 8 s, with ten trials each of CS+ (paired with US) and CS- (unpaired) trials. In extinction (USs omitted), in order to obtain non-autonomic indices of processing and thereby test the information-processing account of "unaware" autonomic conditioning during extinction, a dichotic listening task was implemented, with the CSs presented in the unattended channel (ear), while the subject had to perform a semantic differential reaction task in an attended-to channel (other ear). In early extinction, the electrodermal response occurring at an interval of 9-15 s after CS onset (i.e., following placement of the US during acquisition) and the finger-pulse-volume response occurring at an interval of 4-11 s after CS onset both showed reliable conditioning, but reaction-time and subjective-report data for the recognized critical words indicated serial rather than parallel processing of the CSs during extinction.

Sexually dimorphic cognitive style in rats emerges after puberty.

In a water maze (WM), rats employ different and sexually dimorphic behavioral strategies to solve a place-learning task, a test of cognitive/propositional ability. Puberty is the last step in brain development and marks an important phase with regard to sexually dimorphic cognitive performance and behavior. The present study assessed possible sex differences in cognitive style before and after puberty in a WM place-learning task. Since nitric oxide (NO) is implicated in spatial learning and hippocampal function, and since brain NO(-)(2) + NO(-)(3) levels (stable metabolites of NO) display region-specific sex differences in rat brain, NO(-)(2) + NO(-)(3) levels were determined after behavioral testing. The sex-related style difference emerged very clearly but only in the adult rats, which suggests that the female behavioral strategy in the WM place-learning task requires the presence of female sex hormones at puberty. Although NO(-)(2) + NO(-)(3) levels were higher in the adult rats and males compared to prepubertal and female rats, respectively, no significant correlations emerged between brain NO and behavior. The fact that the behavioral sexually dimorphic cognitive-style effect observed here and in previous studies appears to emerge only after puberty suggests that awareness of such postpubertal sex differences may also be important in human educational and therapeutic contexts.

Sexually dimorphic cognitive style, female sex hormones, and cortical nitric oxide.

Recent studies using the water maze (WM) found marked sex differences in behavioral strategy employed in place learning tasks in adult rats. When a change in the platform position is introduced following learning the place of a platform (visible or hidden) in a different position, female rats escape to the newly positioned visible platform faster than males. Nitric oxide (NO) is implicated in place learning, and there are regional sex differences in its stable metabolites, NO(2)(-)+NO(3)(-), in rat brain. Furthermore, NO(2)(-)+NO(3)(-) levels are sensitive to ovariectomy in female rats. The effect of sex hormones on brain development and function is well documented. The present study was undertaken to study the effects of ovariectomy and hormonal manipulations on cognitive performance in a WM task designed to test differences in behavioral strategy in Sprague-Dawley rats (n=48) of both sexes. Some of the females rats were ovariectomised and received either hormone replacement (estrogen or progesterone alone or in combination) or the vehicle. Cortical and hippocampal NO(2)(-)+NO(3)(-) levels were determined after behavioral testing. There were no group differences in cognitive ability or non-cognitive factors such as motivation or swim speed. Males and intact females differed in their cognitive style, but hormonal manipulations in female rats did not affect this relative use of behavioral strategy. There was a correlation between performance on the trial where sex differences were most prominent and NO(2)(-)+NO(3)(-) levels in the cortex. Our results suggest that the activational effects of circulating gonadal hormones do not play a major role in sexually dimorphic cognitive styles.

Commentary: On the limited role of the "single-subject" design in psychology: hypothesis generating but not testing.

The "single-subject" design (which really denotes a design that employs too few subjects to allow statistical inferences concerning significance to be made) is useful only for the generation, but not for the testing or evaluation, of hypotheses concerning any psychological function. Those hypotheses that may be suggested by the "single-subject" design include ones about within-subject developmental effects (which may need to be studied over multiple sessions), as well as individual-difference-related variables. To adequately test any of those hypotheses, however, it is necessary to employ designs that vary both within- and between-subject factors, and that also examine various correlations in such a way that all effects (including correlational ones) can be evaluated by conventional modes of statistical inference.

Sexually dimorphic effect of an acute smoking manipulation on skin resistance but not on heart-rate during a cognitive verbal task.

In a two-day, two-session experiment where smokers male and female college-student subjects worked on a cognitive verbal task during either the first or second day, and on a cognitive spatial task on the second or first day, smoking was manipulated as an acute independent variable by requiring 10+ hours of pre-experimental abstention, and providing a cigarette during the 15-minute rest period between the two sessions. Non-smoker female and male subjects underwent the same experiment, and hence served as controls for the effects of this acute-smoking manipulation. Overall adaptation (decreased arousal) to the experiment was manifested in a significant increase in skin resistance level (SRL) in all subjects, but when this adaptation effect was statistically controlled, there was a significant smokers by sex interaction during the verbal task only, such that SRL was increased by the cigarette in males, but decreased in females. In contrast, the same analysis indicated only a marked increase in heart-rate (HR) due to smoking, which was unaffected either by sex or by whether the task was the verbal or the (easier) spatial one. We interpret the SRL results as reflecting a sex difference in the direction of transient psychological arousal, and discuss it in relation to evidence in the literature based on self reports, and to evidence (based on HR in this study and on blood pressure in other studies) on physiological (cardiovascular) arousal. Key Words: Electrodermal activity, heart-rate, psychological vs. physiological, verbal and spatial cognitive tasks.

Nicotine interacts with sex in affecting rat choice between "look-out" and "navigational" cognitive styles in the Morris water maze place learning task.

The effect of sex and nicotine on cognitive style was examined in rats using a water maze task that allows differentiation between cognitive ability and style. During the 12-day acquisition period with the platform in the same location (either visible or hidden) there were no effects or interactions attributable to nicotine and sex, either in terms of learning rate or asymptotic latency. On the final test day the platform was visible and shifted in its location, and on the first trial the new location was proximal to the rats starting position, in contrast to the more distal location of the platform during the previous acquisition days. This platform relocation presented the rats with a choice between two competing cognitive styles: using local visual (look-out) cues vs. navigational cues. Performance on the test day yielded a nicotine x sex interaction, such that only saline-treated female rats showed a clear preference for the perceptual-proximal look-out cognitive style by swimming straight to the newly-relocated visible platform with mean escape latency that approximated the limits of swimming speed. The other three groups did not differ from each other, and preferred navigational cues. The results show that male and female rats use different strategies in problem solving, and that nicotine shifts the female pattern to that of the male.

Intersession interval affects performance in the Morris Water Maze.

We have recently reported an effect that shows a sexually dimorphic difference in cognitive style rather than ability. The preparation for potentially producing this proximal perceptual style effect is one where rats are first given 4-trial daily acquisition sessions for 12 days with the platform always in the same position, but sometimes visible (perceptual, "look-out" condition) and sometimes hidden (conceptual, "navigational" condition). On the first, probe trial of the 13th day, the platform's position is shifted to a point very close (proximal) to the rat's starting position, and made visible. The proximal perceptual style (PPS) effect has emerged sexually dimorphically in that only females swam straight to the newly positioned proximal platform. Other studies have shown that the PPS effect is eliminated (with females behaving like males) by nicotine and prepubertal ovariectomy, and does not occur in prepubertal females. Also, as no sex-related effects emerged during acquisition during these studies, the PPS effect appears to be a function of cognitive style rather than ability. The present study varied age, and, in an effort to economize on time, shortened acquisition to 6 days by having morning and afternoon sessions each day. To our surprise, this relatively subtle psychological manipulation eliminated the PPS effect, and also yielded some sex- and age-related effects during acquisition: A male advantage was observed and prepubertal rats had longer escape latencies; there was no significant interaction between sex and age.

Effects of tobacco smoking and gender on interhemispheric cognitive function: performance and confidence measures.

Cognitive function in tasks involving interhemispheric processing of verbal and spatial information was studied in 31 college students in a 2 x 2 factorial design with chronic smoking status [smoker (10+ cigarettes per day) versus non-smoker (no history of smoking)] and gender as the main between-subject factors. The subjects participated in two sessions on two consecutive days. The same task was repeated within the same session with a 15 min interval: smokers were tested before and after smoking whereas non-smokers rested during the interval. Dependent behavioral variables included those of performance (speed and accuracy) and confidence (low rate of non-responding). The verbal task yielded an expected female advantage, and smoking had the gender-specific effect of increasing both speed and accuracy more clearly in males. In addition, smoking decreased the rate of non-responding (increase confidence) in women, thereby affecting preferred strategies for problem solving by shifting the female pattern towards the male pattern. The spatial task, which probably involved a more perceptual, rather than cognitive, level of functioning, produced no clear effects of smoking and gender, and yielded some laterality effects. The acute within-subject smoking manipulation wherein, among smokers, the first test was preceded by 10+ h of deprivation, whereas the second repeated task was preceded by the smoking of a cigarette (i.e. deprivation followed by partial release) did not affect the behavioral measures. In conclusion, smoking had a gender-specific effect on cognitive function: it improved the performance of males in a verbal task and increased the subjective confidence of females thereby affecting the preferred cognitive strategies for problem solving.

Relations among memory performance, mental workload and cardiovascular responses.

The levels of processing paradigm has been a powerful research framework in the study of memory for close to a quarter century. However, an objective index of depth of processing is still lacking. Two experiments using lists of words, presented to male subjects, wee performed to compare the effects of depth of processing, rate of presentation, and task incentive on recognition memory performance, self-reported workload, and cardiovascular responding. Memory performance results from the two experiments demonstrated higher recognition levels associated with deeper processing and slower presentation rates. Deeply encoded items were associated with faster recognition latencies. Self-reported workload levels were higher for deeper processing and faster presentation rates. Cardiovascular responses were generally amplified with the addition of a task incentive. Increased blood pressure was associated with faster presentation rates. Increased heart rate and decreased T-wave amplitude (i.e., increased sympathetic activity) were uniquely associated with the deep encoding of information presented at the fastest rate. This particular encoding condition was associated with increased recognition levels. Deeply encoded items were associated with increased suppression of heart rate variability during recognition. This combination of behavioral and cardiovascular measures may provide the basis for an objective index of depth of processing.

Effects of psychological and physiological challenges on heart rate, T-wave amplitude, and pulse-transit time.

The reactive sensitivities of T-wave amplitude (TWA), pulse-transit time (PTT) and heart rate (HR) were examined in response to psychological, physiological, and combined challenges. In one experiment, 20 subjects performed 1-min arithmetic and combined arithmetic-with-cycling tasks, with HR and TWA being measured. The former showed significant reactive sensitivity, but TWA attenuation reached significance only in the combined challenge situation. In another experiment, 18 males performed 1 min arithmetic tasks, before, during, and following sustained low and moderate intensity cycling. Pulse-transit time was also gauged in this second study. The results showed that HR increased reliably to all challenges, TWA attenuated in response to the arithmetic task both at rest and during exercise, but displayed the paradoxical augmentation to sustained exercise, and PTT decreased significantly to exercise, but it did not decrease reliably to the arithmetic task in any of the conditions. These results suggest that the time course (tonic versus phasic) of the challenge, rather than its psychological or physiological nature, may be the determinant factor in TWA reversal.

Some elementary distinctions among, and comments concerning, the 'control' question 'test' (CQT) polygrapher's many problems: a reply to Honts, Kircher and Raskin.

Although the title of Honts et al.'s paper suggests that it will be a reply to the specific, logico-ethical problem of the CQT polygraph (the Polygrapher's Dilemma), the text deals only tangentially with this logico-ethical problem, and engages, instead, in a diffuse discussion of related, but different, ethical, methodological, and empirical problems of the CQT polygraph. This paper seeks to restore some clarity to the discussion by reminding us of certain basic distinctions among logico-ethical, ethical, methodological, and empirical problems. In the light of these distinctions, the relevant literature, and the essential characteristics of the CQT (which continue to be obscured by the use of systematically misleading terminology), I stand by my claim that, on the ethico-logical grounds (i.e. the CQT Polygrapher's Dilemma formulated in my 1993 paper [1]), as well as ethical, methodological, and evidential grounds (which have been detailed elsewhere), the CQT should be abandoned as a serious method of detecting deception, no matter how useful it may be to practitioners as an interrogatory prop.

The North American polygraph and psychophysiology: disinterested, uninterested, and interested perspectives.

From both a scientific and an applied psychophysiological point of view, the related but different ideas of using physiological measures to differentiate and detect deception are of considerable potential interest. This paper's primary concern is with psychophysiological detection, and it is mainly focused on the North American 'Control' Question 'Test' (CQT). The treatment is disinterested in the sense that there is an insistence on employing fundamental terms in a logically consistent way. Following a detailed description of the CQT, and an analysis of it and related psychophysiological deception procedures, it is suggested that, by and large, the North American research psychophysiological community has failed to measure up to the standards of disinterestedness with respect to the psychophysiological detection of deception. Instead it has adopted an uninterested perspective, which has allowed the interested community of professionals who employ the CQT to hood-wink both themselves and others (including the American Psychological Association) that the CQT is a controversial, but scientifically based, test for detecting deception. As the most cognate organization, the international psychophysiological research community needs to take a more active and disinterested role in this salient purported application of psychophysiology--the detection of deception.

PRES- and orthostatic-induced heart-rate changes as markers of labile hypertension: magnitude and reliability measures.

Split-half and test-retest reliabilities of heart-rate responses to a baroreceptor manipulation and an orthostatic maneuver were compared between subjects with either normal or elevated blood-pressure. Ten subjects showing elevated resting blood-pressure and II normotensive subjects participated in two experimental sessions, each including heart-rate recordings during baroreceptor manipulation and orthostatic challenge. Carotid baroreceptors were manipulated by applying the baroreceptor-specific phase-related external suction (PRES) technique. The orthostatic stimulation procedure (OSP) was a change of body position from lying to standing. Heart rate responses evoked by OSP failed to discriminate significantly between the groups either in the magnitude or the (test, retest) reliability measure. The PRES procedure also failed to discriminate with the conventional magnitude measure, but the reliability measures showed significant differences. Paradoxically, the high-blood-pressure group manifested the higher baroreceptor reliability. The present findings are consistent with the view that operant conditioning produces phasic blood-pressure increases. In this view, blood-pressure increases activate the arterial baroreceptors which, in turn, dampen pain and/or stress sensitivity. Individuals showing high consistency (reliability) in their cardiovascular responses are more likely to learn this form of conditioning, and hence to eventually increase their tonic blood-pressure. High reliability of cardiovascular responses may therefore constitute a risk for hypertension. Aside from such theoretical considerations, the findings indicate that less conventional dependent variables like reliability may be worth exploring in the search for the etiology of essential hypertension, and that, in this search, specificity (relative to baroreceptor function) is more important than the magnitude of the heart-rate changes that are produced.

Electrodermal differentiation of deception: the effect of choice versus no choice of deceptive items.

In the differentiation-of-deception paradigm (DDP), the experimental and control conditions, respectively, consist of questions answered deceptively (D) and honestly (H). Previous DDP studies with the electrodermal SCR as the dependent variable have yielded the basic increase in responding to D relative to H questions (D > H), and have indicated that this effect is probably not due to cognitive factors such as differential retrieval difficulty, and is also relatively unaffected by motivational factors. To test the notion that the D > H effect does not represent genuine deception because of the elimination of the element of choice in the DDP, the present study varied, between two groups of 16 subjects, the degree to which subjects could choose which questions they would answer deceptively. If choice were necessary, or even important, for the differentiation-of-deception phenomenon, the D > H effect should have been greater in the free-choice condition, but the (nonsignificant) trend was in a direction opposite to this prediction. Another orthogonally-varied, between-subject manipulation, was the relative frequency of D and H items. The basic electrodermal D > H phenomenon, including the curious lack of response habituation during the session, has now been duplicated over a variety of conditions, but the mechanisms underlying the phenomenon are far from being well understood.