Playgroup attractiveness studied with information integration theory

Playgroup attractiveness was studied in two critical tests of information integration theory. In Experiment 1, the ratio of good to bad members in the group, and the number of toys available to the group, were varied in a 4 × 4 factorial design. The results obeyed the parallelism prediction of the theory, thereby indicating that group attractiveness was a sum or an average of the two given pieces of information. Experiment 2 provided a critical qualitative test between the adding and averaging hypotheses. The results eliminated the adding rule, supported the averaging rule. These results illustrate the potential power that integration theory provides to the experimental study of group attractiveness in children.     

Learning impairment following insoluble problems: Learned helplessness or altered hypothesis pool?

According to the learned helplessness hypothesis, the learning impairment typically displayed by subjects previously given insoluble problems results from the veridical learning of response-outcome independence. This learning is represented as a belief in helplessness which interferes with the subsequent acquisition of adaptive responses. However, this interpretation is suspect since subjects in a psychology experiment tend not to learn that random relationships are random. Instead, an alternative interpretation of these findings attributes the learning impairment following insoluble problems to a hypothesis pool alteration in the direction of (inappropriately) complex hypotheses. This alternative interpretation tended to be supported ported in Experiment 1, which varied the difficulty of the test task and found the impairment (relative to a no-treatment control) following insolubility to be inversely proportional to the test difficulty. In contrast, Experiment 2 employed a procedure which facilitated the attribution of response-outcome independence and found the impairment following insolubility to be directly proportional to the test difficulty. It was concluded that the results of Experiment 2 represented learned helplessness.     

Effects of UCS intensity and postpeak acquisition trials on classical conditioning of the SCR

The present study examined the effects of UCS intensity and number of postpeak acquisition trials on classical conditioning and extinction of the SCR. A 2 × 3 design was employed in which subjects received either a 1, 2, or 4 mA shock UCS and either two or 16 acquisition trials beyond the peak CR. While conditioning was demonstrated during acquisition, there was no relationship between strength of conditioning and intensity of UCS. The phenomenon of stronger resistance to extinction following fewer acquisition trials (e.g., two past the peak CR) than with many (e.g., 16 past the peak CR) was demonstrated only for the groups that were conditioned with the 4 mA UCS. Resistance to extinction varied positively with UCS intensity, but only for the subjects who received two postpeak acquisition trials. Sixteen trials beyond the peak CR resulted in the UCS intensity having little or no effect on resistance to extinction.     

A serendipitous field experiment in job design

A longitudinal study over a 5-month period of changes in several jobs was conducted among 244 employees of a federal agency. Seventy-one employees at a single location constituted an experimental group in which the changes were made. An additional 173 employees at scattered field locations formed a comparison group. Data were obtained on perceptions of job content and a number of job attitudes. The data indicated a temporary positive influence of the changes in one set of jobs. People in a group of clerical jobs, however, experienced a “deenrichment” of their jobs as a result of the changes with an accompanying negative effect on their job attitudes and motivation.     

Implications of evaluating and intervening with incipient stutterers

A study was conducted to investigate the factors involved in the recovery from incipient stuttering without therapeutic intervention. Fifteen subjects were seen on two occasions, once for an initial evaluation after the reported onset of stuttering, and for a second evaluation to determine if they had recovered or become chronic stutterers. Within the constraints of a small sample, several findings are presented: (1) 80% of the children recovered spontaneously from stuttering, (2) subjects who exhibited more types and frequencies of disfluencies upon onset had a poorer prognosis for recovery, (3) the age of onset, if under 4 years, had little bearing on recovery, and (4) children who were seen professionally soon after disfluency onset had the greatest prognosis for recovery. Possible implications of these results are discussed.     

Patterns of spontaneous recovery in aphasic groups: A study of adult stroke patients

The recovery of 31 aphasic stroke patients in the first three months postonset was investigated. Improvements on eight comprehension, repetition, and expression tasks were documented for four groups. These groups, retrospectively defined on the basis of initial scores on a fluency and a comprehension task, were: Low Fluency/Low Comprehension (LFLC), Low Fluency/High Comprehension (LFHC), High Fluency/Low Comprehension (HFLC), and High Fluency/High Comprehension (HFHC). Examination of each group's recovery revealed (1) equal improvement on nearly all language tasks for the two High Comprehension groups and (2) a more selective improvement largely in comprehension and imitation tasks for the two Low Comprehension groups. Implications of this selective improvement in initially low comprehending aphasics are discussed.     

Confrontation naming impairment in dementia

In tone languages pitch variations (tones) serve to distinguish the lexical meanings of words. This study was conducted to examine the extent and nature of impairment in the perception of tones by aphasic patients who were monolingual speakers of Thai, a tone language which has five contrastive tones (mid, low, falling, high, rising). Six subjects participated in the study: two Broca aphasics, one transcortical motor aphasic, one conduction aphasic, one right brain-damaged nonaphasic, and one normal control. Three sets of stimuli (two real-speech, one synthetic-speech) were presented for identification, each set containing five Thai words minimally distinguished by tone. Results of the perception tests indicated that the performance of all four left brain-damaged aphasics differed significantly from that of the normal control, while the performance of the right brain-damaged nonaphasic did not. The normal performance of the right brain-damaged nonaphasic patient on this tone identification task suggests that deficits in the perception of tone exhibited by left brain-damaged patients can be attributed specifically to pathology in the language dominant hemisphere rather than to a general brain-damage effect. No difference in performance among the left brain-damaged patients could be attributed to a specific type of aphasic syndrome. The pattern of tonal confusions of the aphasics in comparison to that of normals suggests that their deficit is primarily quantitative rather than qualitative. Although two (mid, low) of the five tones accounted for a large percentage of the aphasics' errors, no uniform rank order of tones in terms of identifiability could be established across aphasic subjects, which suggests that their deficit is general to all five tones rather than selective to individual tones.     

The effect of repetition on search through active memory

Short lists of digits, some of which contained repeated items, were searched in memory. Repeated items were recognized faster than non-repeated items. Search times for non-repeated items in lists with a repeat were slightly faster than those for lists of the same length in which no items were repeated. A serial position effect was found such that items at either the beginning or end of the memory list were responded to faster than items in the middle of the list. Neither the repeated digit effect nor the serial position effect support serial exhaustive search. An empirical equation was found by which response time is predicted by the log proportion of items in a memory list that match the test stimulus. These results are compatible with the notions of neural pathway activation and trace strength.     

Individual differences in learning and memory: A unitary information processing approach

Recent research in the area of individual differences in learning and memory is reviewed from a cognitive perspective. Using the two-state model of memory as a framework, individual variations in attentional, short-term store, and long-term store processes are discussed. The focus is on using individual differences to evaluate nomothetic cognitive models, as well as on using cognitive models in guiding research on individual differences. Both within-individual and between-individual differences in basic processes are examined. In so doing, the importance of strategy choice is stressed using the concept of cognitive flexibility. Several promising directions, both methodological and theoretical, are noted and the value of using specific information processing models in the study of individual differences is emphasized.