Event-related potentials, reaction time, and response selection of skilled and less-skilled cricket batsmen

The differences in P300 latency, P300 amplitude, response selection, and reaction time between skilled and less-skilled cricket batsmen have been investigated. Eight skilled and ten less-skilled right-handed batsmen each viewed 100 in-swing, 100 out-swing, and 40 slower deliveries displayed in random sequence from projected video footage whilst their responses and electroencephalograms were recorded. Logistic regression was used to derive a discriminative function for the P300 data. This was done to determine whether the skilled batsmen differed from the less-skilled batsmen on the basis of pooled P300 amplitude and latency data. All the batsmen were correctly characterised as being skilled or less-skilled. Logistic regression equations with reaction time and correctness of response data indicated that behavioural data do not correctly classify skilled performance. It is suggested that skilled cricket batsmen have a superior perceptual decision-making ability compared with less-skilled cricket batsmen, as measured by P300 latency and amplitude. This appears to be the first study showing a link between skill and cerebral cortical activity during a perceptual cricket batting task and it could pave the way for future studies on mental processing in cricket batsmen.     

Differential stability and individual growth trajectories of big five and affective traits during young adulthood

Big Five and affective traits were measured at three assessments when participants were on average 18, 21, and 24 years old. Rank-order stability analyses revealed that stability correlations tended to be higher across the second compared to the first retest interval; however, affective traits consistently were less stable than the Big Five. Median stability coefficients for the Big Five increased from .62 (Time 1 vs. Time 2) to .70 (Time 2 to Time 3); parallel increases also were observed for measures of negative affectivity (median rs=.49 and .55, respectively) and positive affectivity (median rs=.48 and .57, respectively). Growth curve analyses revealed significant change on each of the Big Five and affective traits, although many of the scales also showed significant variability in individual trajectories. Thus, rank-order stability is increasing for a range of personality traits, although there also is significant variability in change trajectories during young adulthood.     

Effectiveness of Cognitive/Behavioral Small Group Intervention for Reduction of Depression and Stress in Non-Hispanic White and Hispanic/Latino Women Dementia Family Caregivers: Outcomes and Mediators of Change

This study enrolled 184 middle-aged and older women (95 Non-Hispanic White and 89 Hispanic/Latino) who provided in-home hands-on care to an elderly relative with Alzheimer’s disease or another form of dementia. Within ethnic group they were randomly assigned to either a CBT-based small group intervention program called “Coping with Caregiving” (CWC) that taught a variety of cognitive and behavioral skills to reduce stress and depression, or to a minimal telephone based control condition (TSC). Intervention lasted about 4 months; one post-treatment assessment was completed 6 months after baseline by interviewers blind to the intervention condition. Interviews and interventions were conducted in English or Spanish by trained staff. Results indicated that those in the CWC (regardless of ethnicity) showed greater improvement from pre to post intervention than those in the TSC on measures of depressive symptoms, overall life stress, and caregiving-specific stress. In order to investigate if these changes may have been related to one proposed mechanism of change in CBT (skill utilization), a new measure was constructed. Change in frequency of use and perceived helpfulness of adaptive coping skills were assessed in all caregivers. Results indicated that caregivers in CWC reported greater frequency of use, and greater perceived helpfulness, of these skills at post intervention compared to caregivers in the TSC. Improvement measured by dependent measures was correlated with an increase in these indices for those in the CWC. Tests for mediation suggest that effective skill utilization may mediate the effect of treatment on outcome. Implications of these findings are discussed and recommendations provided for future research.     

Do wild New Caledonian crows (<Emphasis Type="Italic">Corvus moneduloides</Emphasis>) attend to the functional properties of their tools?

New Caledonian crows are the most proficient non-hominin tool manufacturers but the cognition behind their remarkable skills remains largely unknown. Here we investigate if they attend to the functional properties of the tools that they routinely use in the wild. Pandanus tools have natural barbs along one edge that enable them to function as hooking implements when the barbs face backwards from the working tip. In experiment 1 we presented eight crows with either a non-functional (‘upside-down’) or a functional pandanus tool in a baited hole. Four of the crows never flipped the tools. The behaviour of the four flipping birds suggested that they had a strategy of flipping a tool when it was not working. Observations of two of the eight crows picking up pandanus tools at feeding tables in the wild supported the lack of attention to barb direction. In experiment 2 we gave six of the eight crows a choice of either a barbed or a barbless pandanus tool. Five of the crows chose tools at random, which further supported the findings in experiment 1 that the crows paid little or no attention to the barbs. In contrast, a third experiment found that seven out of eight crows flipped non-functional stick tools significantly more than functional ones. Our findings indicate that the crows do not consistently attend to the presence or orientation of barbs on pandanus tools. Successful pandanus tool use in the wild seems to rely on behavioural strategies formed through associative learning, including procedural knowledge about the sequence of operations required to make a successful pandanus tool. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Error detection and posterror behavior in depressed undergraduates

This study examined the influence of depression on error-monitoring and behavioral compensation after errors, two important aspects of cognitive control. Undergraduates differing in self-reported depression levels completed a modified Stroop task while error-related scalp potentials were recorded. Behaviorally, participants with higher depression scores were disproportionately slower and less accurate after errors in a task condition that included negative emotional words. Physiological results indicated that the amplitudes of the error-related negativity (ERN) and error positivity (Pe), two indices of error detection, were not correlated with depression score. ERN amplitudes predicted behavioral slowdown after errors, but only among more depressed participants in the negative-word condition. Together, the results imply that depression is associated not with an error detection deficit, but rather with alterations in subsequent performance changes, once errors have been identified.     

Gender Differences in the Relationship of Anger and Depression in a Clinical Sample

This study examined the relationship of anger dimensions with depression in a clinical sample. Results suggest that the differences between women and men in nonclinical samples typically used in this research may not generalize completely to clinical samples. Further evidence is presented to support the contention that the relationship between anger and depression is important for both men and women.     

Personality and modulation of the startle reflex by emotionally-toned filmclips

Several researchers have found that pleasant foreground stimuli attenuate the eyeblink component of the startle reflex while unpleasant foreground stimuli potentiate it. The effects of personality factors on such modulation of the eyeblink response, as measured by electromyographic (EMG) activity in reaction to loud acoustic startle probes, were examined in subjects viewing emotionally-toned (pleasant, unpleasant and neutral) filmclips. During the main part of the experiment, introverts had higher baseline EMG activity and lower response probability than extraverts; no differences were observed at the beginning of the experiment, during an acclimatization session. Reflex modulation, as measured by response latency, was influenced by the Psychoticism (P) factor of the Eysenck Personality Questionnaire: subjects high on P showed longer latencies to eyeblink onset when probed during viewing of pleasant filmclips than subjects low on this dimension; no significant differences were observed between subjects low and high on P for neutral and unpleasant filmclips. No influence of personality factors was found on affective modulation as measured by response amplitude/magnitude. The results are discussed in relation to Gray's and Eysenck's theories of personality.