Predictive laws of association in statistics and physics

In the present paper we face the problem of estimating cell probabilities in the case of a two-dimensional contingency table from a predictive point of view. The solution is given by a double stochastic process. The first subprocess, the unobservable one, is supposed to be exchangeable and invariant. For the second subprocess, the observable one, we suppose it is independent conditional on the first one.     

Depression and Suicidal Ideation After Predictive Testing for Huntington's Disease: A Two-Year Follow-up Study

The present study reports a two-year follow-up of psychological effects of predictive testing for Huntington's disease. Questionnaires assessing depression, general health, well-being, self injurious behavior, life satisfaction, and lifestyle were completed by 35 carriers and 58 non-carriers before the predictive test, and 2, 6, 12, and 24 months afterwards. Both carriers and non-carriers showed high suicidal ideation before the predictive testing. Depression scores and frequency of suicidal thoughts increased for carriers, compared to non-carriers, over time. There were no differences regarding life satisfaction or life style between carriers and non-carriers. Predictive testing was beneficial in reducing overall ill-health symptoms and increasing well-being for those initially expressing concern about Huntington's disease. The importance of assessing suicidal ideation and of continuing to provide adequate support is emphasized.     

The planning and execution of short auditory sequences

Action planning, but not action execution, in speeded tasks is typically faster when responses and their effects are compatible than when they are incompatible. We tested whether response-effect compatibility (REC) affects the execution of music-like sequential actions that require temporal regularity rather than rapidity. Musicians responded to metronomic visual stimuli by producing sequences of three taps at a specific tempo on three vertically aligned keys. Each tap triggered a tone. Key-to-tone mapping was either compatible or incompatible in terms of spatial height and pitch height. The results indicated that tap timing was more accurate with compatible than with incompatible mappings, both for taps produced before (Tap 1) and after (Taps 2 and 3) the onset of auditory feedback. Thus, the observed influence of REC on action execution was not due exclusively to actual auditory feedback. The anticipation of distal action effects may be involved in planning the dynamics of temporally precise movements.     

The psychology of engagement with indigenous identities: a cultural perspective

In a questionnaire study among 124 students at Haskell Indian Nations University, the authors investigated the hypothesis that engagement with Indigenous identity--assessed along three dimensions including degree (identification scale), content (panethnic or tribal nation), and context (reservation or nonreservation)--can serve as a psychological resource for well-being and liberation from oppression. Consistent with this hypothesis, degree of identification was positively correlated with community efficacy and perception of racism. Apparently inconsistent with this hypothesis, degree of identification among students who had resided on a reservation was negatively correlated with the Social Self-Esteem subscale of the Current Thoughts Scale. Rather than evidence against the identity-as-resource hypothesis, this pattern may reflect the cultural grounding of self-esteem and tools designed to measure it.     

Correlates of tattoos and reference groups

520 college students from a public university in the southwest were questioned to examine correlations between having a tattoo and the presence of tattoos among their family and friends. Tattoos among both friends and family were positively correlated with respondents' having a tattoo. The magnitude of friends' influence was about double the influence of family.     

Task-set inertia and memory-consolidation bottleneck in dual tasks

Three dual-task experiments examined the influence of processing a briefly presented visual object for deferred verbal report on performance in an unrelated auditory-manual reaction time (RT) task. RT was increased at short stimulus-onset asynchronies (SOAs) relative to long SOAs, showing that memory consolidation processes can produce a functional processing bottleneck in dual-task performance. In addition, the experiments manipulated the spatial compatibility of the orientation of the visual object and the side of the speeded manual response. This cross-task compatibility produced relative RT benefits only when the instruction for the visual task emphasized overlap at the level of response codes across the task sets (Experiment 1). However, once the effective task set was in place, it continued to produce cross-task compatibility effects even in single-task situations (“ignore” trials in Experiment 2) and when instructions for the visual task did not explicitly require spatial coding of object orientation (Experiment 3). Taken together, the data suggest a considerable degree of task-set inertia in dual-task performance, which is also reinforced by finding costs of switching task sequences (e.g., AC → BC vs. BC → BC) in Experiment 3.     

Task switching and action sequencing

We investigated if task switching affects late response processes that occur after the selection of a response. Subjects performed a sequence of two responses. The first and second response were selected, and then executed in close succession. The interresponse interval (IRI) was taken as a measure of late response processes. The two responses could either belong to different tasks (task-switch condition), or to the same task that was performed twice (task-repetition condition). In all three experiments, the IRI was found to be longer in the task-switch condition than in the task-repetition condition, consistent with the idea that task switching affected late response processes. However, the effects of the manipulation of the stimulus-onset asynchrony revealed that the tendency to perform the two responses as a sequence was reduced in the task-switch condition relative to the task-repetition condition. Thus, the data do not provide unequivocal evidence for task switching affecting late response processes. The data show, however, that task switching affected action sequencing. Two actions that do not belong to the same task context are less likely to be performed as an action sequence. We suggest that task switching interacts with higher-order control processes that cannot be studied within the traditional task-switching paradigm.     

Chunking in task sequences modulates task inhibition

In a study of the formation of representations of task sequences and its influence on task inhibition, participants first performed tasks in a predictable sequence (e.g., ABACBC) and then performed the tasks in a random sequence. Half of the participants were explicitly instructed about the predictable sequence, whereas the other participants did not receive these instructions. Task-sequence learning was inferred from shorter reaction times (RTs) in predictable relative to random sequences. Persisting inhibition of competing tasks was indicated by increased RTs in n- 2 task repetitions (e.g., ABA) compared with n- 2 nonrepetitions (e.g., CBA). The results show task-sequence learning for both groups. However, task inhibition was reduced in predictable relative to random sequences among instructed-learning participants who formed an explicit representation of the task sequence, whereas sequence learning and task inhibition were independent in the noninstructed group. We hypothesize that the explicit instructions led to chunking of the task sequence, and that n- 2 repetitions served as chunk points (ABA-CBC), so that within-chunk facilitation modulated the inhibition effect.