A psychophysiological study of the use of partial information in stimulus-response translation.

Ss performed a hybrid go/no-go reaction task in which colored letters were assigned in various ways to 4 finger responses, 2 on each hand. In addition to reaction time, psychophysiological measures were used to assess the duration of stimulus identification and the onset of central and peripheral motor activity. The results suggest that response selection can begin on the basis of 1 stimulus dimension (e.g., color), while the other dimension (e.g., letter form) has not yet been identified. Other results are discussed with regard to "selection for action" (Allport, 1987) and the importance of stimulus-response translation strategies in the use of partial information.     

Analytic,synthetic, abstracting,and word-class-defining aspects of verbal mother-child interactions

Phenomena of language teaching and learning in the course of verbal interactions between one mother and her daughter were analyzed. The daughter was between 18 and 27 months old during the recordings, and her utterance length ranged from 1,5 to 4,0 morphemes. Twenty hours of interactions were analyzed and the emphasis was placed upon sequential aspects and mathemagenic features of the conversations. It was demonstrated that the mother performs much analytic, synthetic, abstracting, and word-class-defining work during these verbal interactions. These maternal instructional activities seem to lead not only to the child's learning of language rules but also to her employment of the abstracting, analytical, and synthetic methodology. It is concluded that the main explanatory focus has to be on the mother in the attempts to explain language transmission and acquisition. Basic similarities to other instructional/skill training situations are suggested. Neither extraordinary complex cognitive nor innate linguistic capacities need to be assumed to explain the phenomena in question.     

Can we predict non-response in developmental tasks? Assessing the longitudinal relation between toddlers' non-response and early academic skills

To date, virtually no studies have examined toddlers' non-response in developmental tasks. This study investigates data from 3667 toddlers to address (1) whether two aspects of non-response (completion and engagement) are separable, (2) how stable these aspects are from ages two to three, (3) how non-response relates to background characteristics, and (4) whether non-response at ages two and three predicts early academic skills at age six. Structural equation modelling shows that completion and engagement are separable constructs, relatively stable across age, and related to several background characteristics. Especially engagement predicts later academic performance. Results show that non-response in behavioural tasks in toddlers is not random, increasing the likelihood of sampling bias and lack of generalizability in developmental studies.     

Selective response activation can begin before stimulus recognition is complete: a psychophysiological and error analysis of continuous flow

In discussions of process models of human information processing, the continuous flow conception (Eriksen and Schultz 1979) plays a prominent role. A central prediction of this conception is that any information in a display associated with a response activates that response as soon as it becomes available in the perceptual system. If it concerns the correct response channel, then response facilitation occurs. If it concerns the incorrect response channel, then response competition occurs. To assess these mechanisms more directly, we used psychophysiological measures as well as reaction time (RT). We used the latency of the P3 component of the event related brain potential (ERP) as an index of stimulus evaluation duration, the onset of lateralized motor activity derived from the ERP as an index of selective central motor activation, and the onset of electromyographic activity as an index of the start of peripheral motor activation. Subjects were required to respond to target letters that were either flanked by letters that signalled the opposite response (incompatible arrays), by the target itself (compatible arrays), by letters not associated with a response (neutral arrays), or by no other letters (targets alone). Our results replicated the basic findings obtained in this paradigm. RTs to targets alone did not differ from RTs to compatible arrays. The latter were faster than RTs to neutral arrays, which were faster than RTs to incompatible arrays. P3 latencies were longer on incompatible than on neutral trials, and longer on compatible than on target alone trials. Incorrect central response activation on incompatible trials and correct central response activation on compatible trials, both began earlier than on target alone trials. Peripheral responding on both trial types, however, began later than on target alone trials. More incompatible but less compatible trials than neutral ones exhibited incorrect peripheral response activation. Peripheral response execution was faster and more accurate on compatible than on target alone trials, while it was slower and less accurate on incompatible than on neutral trials. These results indicate, that the flankers activated their associated response channel while display evaluation was still going on, and that response facilitation and competition occurred. After applying criteria proposed by Miller (1988), it was concluded that the set of stimulus recognition processes and the set of response activation processes cannot be regarded as independent stages of processing.     

The role of neuroimaging in the discovery of processing stages a review

In this contribution we show how neuroimaging methods can augment behavioural methods to discover processing stages. Event Related Brain Potentials (ERPs), Brain Electrical Source Analysis (BESA) and regional changes in cerebral blood flow (rCBF) do not necessarily require behavioural responses. With the aid of rCBF we are able to discover several cortical and subcortical brain systems (processors) active in selective attention and memory search tasks. BESA describes cortical activity with high temporal resolution in terms of a limited number of neural generators within these brain systems. The combination of behavioural methods and neuroimaging provides a picture of the functional architecture of the brain. The review is organized around three processors: the Visual, Cognitive and Manual Motor Processors.     

Sensorimotor synchronization: Motor responses to pseudoregular auditory patterns

Musically trained and untrained subjects (N=30) were asked to synchronize their finger tapping with stimuli in auditory patterns. Each pattern comprised six successive tonal stimuli of the same duration, the first of which was accented by a different frequency. The duration of interstimulus onset intervals (ISIs) gradually increased or decreased in constant steps toward the end of the patterns. Four values of such steps were used in different trials: 20, 30, 45, and 60 msec. Various time-control mechanisms are hypothesized as being simultaneously responsible for subjects’ incorrect reproduction of the internal temporal ratios of the stimulus patterns. The mechanism of assimilation (of a central tendency) led subjects to enforce a regular (isochronous) structure on the patterns. The influence of other time-control mechanisms (distinction, subjective expression of an accent, sequential transfer) was expressed mainly in differences between intertap onset intervals (ITIs) and the corresponding ISIs at the beginning of the patterns. The duration of the first two ITIs was in the majority of the trials in an inverse ratio to the ratio of the respective ISIs. The distortions resulting from the timing mechanisms concerned were more pronounced in the performance of nonmusicians than in that of musicians.     

The effects of life crisis on psychological adjustment

In this survey study the question was asked how "life crisis," social conditions, and ratings of quality of life are related to psychological adjustment. The survey included 454 residents, and data were collected on five social conditions: income, education, age, marital status, and religious participation; four ratings of life quality: family, personal life, income, and overall quality of life; the number of recent changes in the lives of the respondents; and two indicators of psychological adjustment. These data were analyzed with multivariate analyses of variance and stepwise regression. Life crisis was associated directly with psychological adjustment. Social conditions and life quality ratings also had significant effects. People with high life-crisis scores reported more psychological distress, and poor social conditions appeared to further exacerbate their adjustment problems. Regardless of the magnitude of the crisis, quality of life ratings had sizable effects on reports of psychological adjustment.     

Quantitative amino acid determination in the serum and cerebrospinal fluid in endogenous depressions

The levels of 20 amino acids were measured in the plasma and cerbrospinal fluid of 41 patients with endogenic depressions. The plasma levels of 12 amino acids were found to be significantly lower in the patients than in the control group, but cerebrospinal fluid levels were significantly lower only in the case of taurine, glutamine, phenylalanine and aginine. Comparison of the same amino acid levels in treated and non-treated patients showed that serine and alpha-aminobutyric acid serum concentrations were higher in the nontreated patients. The tyrosine and phenylalanine levels in the cerebrospinal fluid of the patients who had received medicamentous treatment were higher than in the other group.