Cardiorespiratory rhythm-contingent trace eyeblink conditioning in elderly adults.

Learning outcome is modified by the degree to which the subject responds and pays attention to specific stimuli. Our recent research suggests that presenting stimuli in contingency with a specific phase of the cardiorespiratory rhythm might expedite learning. Specifically, expiration-diastole (EXP-DIA) is beneficial for learning trace eyeblink conditioning (TEBC) compared with inspiration-systole (INS-SYS) in healthy young adults. The aim of this study was to investigate whether the same holds true in healthy elderly adults (n = 50, aged >70 yr). Participants were instructed to watch a silent nature film while TEBC trials were presented at either INS-SYS or EXP-DIA (separate groups). Learned responses were determined as eyeblinks occurring after the tone conditioned stimulus (CS), immediately preceding the air puff unconditioned stimulus (US). Participants were classified as learners if they made at least five conditioned responses (CRs). Brain responses to the stimuli were measured by electroencephalogram (EEG). Memory for the film and awareness of the CS-US contingency were evaluated with a questionnaire. As a result, participants showed robust brain responses to the CS, acquired CRs, and reported awareness of the CS-US relationship to a variable degree. There was no difference between the INS-SYS and EXP-DIA groups in any of the above. However, when only participants who learned were considered, those trained at EXP-DIA (n = 11) made more CRs than those trained at INS-SYS (n = 13). Thus, learned performance could be facilitated in those elderly who learned. However, training at a specific phase of cardiorespiratory rhythm did not increase the proportion of participants who learned.NEW & NOTEWORTHY We trained healthy elderly individuals in trace eyeblink conditioning, either at inspiration-systole or at expiration-diastole. Those who learned exhibited more conditioned responses when trained at expiration-diastole rather than inspiration-systole. However, there was no difference between the experimental groups in the proportion of individuals who learned or did not learn.

Attentional Processes in Children With Attentional Problems or Reading Difficulties as Revealed Using Brain Event-Related Potentials and Their Source Localization.

Visual attention-related processes include three functional sub-processes: alerting, orienting, and inhibition. We examined these sub-processes using reaction times, event-related potentials (ERPs), and their neuronal source activations during the Attention Network Test (ANT) in control children, attentional problems (AP) children, and reading difficulties (RD) children. During the ANT, electroencephalography was measured using 128 electrodes on three groups of Finnish sixth-graders aged 12-13 years (control = 77; AP = 15; RD = 23). Participants were asked to detect the direction of a middle target fish within a group of five fish. The target stimulus was either preceded by a cue (center, double, or spatial), or without a cue, to manipulate the alerting and orienting sub-processes of attention. The direction of the target fish was either congruent or incongruent in relation to the flanker fish, thereby manipulating the inhibition sub-processes of attention. Reaction time performance showed no differences between groups in alerting, orienting, and inhibition effects. The group differences in ERPs were only found at the source level. Neuronal source analysis in the AP children revealed a larger alerting effect (double-cued vs. non-cued target stimuli) than control and RD children in the left occipital lobe. Control children showed a smaller orienting effect (spatially cued vs. center-cued target stimuli) in the left occipital lobe than AP and RD children. No group differences were found for the neuronal sources related to the inhibition effect. The neuronal activity differences related to sub-processes of attention in the AP and RD groups suggest different underlying mechanisms for attentional and reading problems.

Attentional processes in typically developing children as revealed using brain event-related potentials and their source localization in Attention Network Test.

Attention-related processes include three functional sub-components: alerting, orienting, and inhibition. We investigated these components using EEG-based, brain event-related potentials and their neuronal source activations during the Attention Network Test in typically developing school-aged children. Participants were asked to detect the swimming direction of the centre fish in a group of five fish. The target stimulus was either preceded by a cue (centre, double, or spatial) or no cue. An EEG using 128 electrodes was recorded for 83 children aged 12-13 years. RTs showed significant effects across all three sub-components of attention. Alerting and orienting (responses to double vs non-cued target stimulus and spatially vs centre-cued target stimulus, respectively) resulted in larger N1 amplitude, whereas inhibition (responses to incongruent vs congruent target stimulus) resulted in larger P3 amplitude. Neuronal source activation for the alerting effect was localized in the right anterior temporal and bilateral occipital lobes, for the orienting effect bilaterally in the occipital lobe, and for the inhibition effect in the medial prefrontal cortex and left anterior temporal lobe. Neuronal sources of ERPs revealed that sub-processes related to the attention network are different in children as compared to earlier adult fMRI studies, which was not evident from scalp ERPs.