Positional differences in performance on members of confusable and nonconfusable letter pairs.

Previous experiments by the present author (see PA, Vols 67:6977 and 70:7125) showed that a parafoveally presented letter is more accurately identified when flanked by a letter to its foveal side than when flanked by one to its peripheral side, but only if the 2 letters are nonconfusable. The present 4 experiments, with 65 undergraduates, indicated that the basis for this confusability–asymmetry interaction is not criterion or response bias, but rather that it occurs earlier in visual processing. In Exp I, the interaction was found when only 1 pair member was reported, thus eliminating response bias requiring the report of both letters as the source of the effect. In Exp II, the data were subjected to signal detection analysis, and the interaction persisted. In Exp III, pair members were presented simultaneously or in rapid sequence, and the interaction was found only with simultaneous presentations. In Exp IV, letters were used with upper- and lowercase counterparts that were quite different in shape. Uppercase letters that were most and least confusable for each S were paired for presentation in their uppercase or in mixed-case forms. The interaction occurred only with uppercase pairs. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processing of information in iconic memory: Differences between nonretarded and retarded subjects.

Compared iconic memory processes of 17 undergraduates and 18 retarded Ss (primarily aged 18–28 yrs; IQ 56–77) in 4 experiments. In Exp I, a partial report paradigm was used in which 6 retarded and 6 undergraduate Ss were presented 6 pictures under 4 intervals (0–500 msec). In Exp II, using 5 Ss in each group the same procedure as in Exp I was used but letters as well as pictures were included. Results show that although overall performance for retarded Ss was poor, they did better with letters than with pictures—a reverse of the finding with undergraduate Ss. In Exp III, 2 retarded Ss were given extended practice and incentive to perform well. Asymptote was reached in 10 days but never equaled performance of unpracticed undergraduates. In Exp IV, using 5 Ss in each group, information load was varied from 1 to 4 items, and a masking stimulus was used to interrupt processing following 6 intervals that lasted up to 250 msec. Results show that (1) there are quantitative differences between intelligence groups in iconic capacity; (2) retarded Ss process information more slowly, a difference that increases with increasing information load; and (3) there are substantive structural differences in iconic memory of retarded and nonretarded Ss. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Context effects on examinations: The effects of time, item order and item difficulty.

Tested the effects of contextual factors, i.e., time, item, chapter, and difficulty arrangement, on test performance. In Exp 1, an advantage for students writing a quiz in the early and middle testing periods was found for an afternoon group; however, early testing, compared to middle and late testing, was a disadvantage for an evening group writing the same quiz. Exp 2 found that neither chapter retrieval cues nor sequenced chapter content order affected exam performance; exam items forward-sequenced with text coverage yielded no advantage over those items that were reverse- or random-sequenced. Exp 3 manipulated both chapter order and within-chapter item order so that exam items in any chapter were not sequenced in the same order as text coverage. There was no advantage to receiving exam questions in one sequence over another. In Exp 4, item arrangement was manipulated according to difficulty level (easy-to-hard, hard-to-easy, and random order). No effect on performance for order of item difficulty was found. Results indicate that contextual factors like time have an effect on overall performance; however, other factors, such as item, chapter and difficulty arrangements, have little or no effect on overall performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processing time and the recall of inconsistent and consistent behaviors of individuals and groups.

Conducted 2 experiments with 138 undergraduates to demonstrate that individual–group distinction is important in obtaining a recall superiority of schema-inconsistent behaviors (Exp I) and to investigate a mechanism hypothesized to underlie these effects that attribute the recall enhancement to extra processing given to inconsistent items (Exp II). It is noted that researchers who have investigated the effect of expectancy on memory for behavioral information have found a recall superiority for schema-inconsistent information; however, this finding occurred most clearly only when an individual, rather than a group, was seen as performing the behaviors. Results of Exp I indicate that, when an observer believed that behaviors were all performed by a single individual, the memory advantage for impression-inconsistent actions was more pronounced than when the observer believed the behaviors were performed by group members. Results of Exp II support the hypothesized mechanism. The relevance of these findings to recent experiments is discussed. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial localization in sequential letter displays.

Conducted 2 experiments with a total of 26 undergraduates to investigate the ability to locate letters presented successively along a horizontal row. The letters were displayed for 5 msec, and the inter-letter interval varied between 0 and 200 msec. In Exp I, localization decreased as the inter-letter interval was increased to 50 msec. With further increments in inter-letter interval, performance improved. However, there was a correlation between the positions of the letters in space and in time. Exp II indicated that the recovery in spatial localization with inter-letter intervals greater than 50 msec is spurious (i.e., it does not occur if the correlation is minimized). (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dispensability of member effort and group motivation losses: Free-rider effects.

Three experiments tested the hypothesis that group members exert less effort as the perceived dispensability of their efforts for group success increases. The resultant motivation losses were termed "free-rider effects." In Exp I, 189 undergraduates of high or low ability performed in 2-, 4-, or 8-person groups at tasks with additive, conjunctive, or disjunctive demands. As predicted, member ability had opposite effects on effort under disjunctive and conjunctive task demands. The failure to obtain a relationship between group size and member effort in Exp I was attributed to a procedural artifact eliminated in Exp II (73 Ss). As predicted, as groups performing conjunctive and disjunctive tasks increased in size, member motivation declined. This was not a social loafing effect; group members were fully identifiable at every group size. Exp III (108 Ss) explored the role that performance feedback plays in informing group members of the dispensability of their efforts and encouraging free riding. Results are generally consistent with those of Exps I and II. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Different rule systems for counting behavior acquired in meaningful and rote contexts of learning.

In a series of 3 experiments, 68 undergraduates learned to a criterion of 2 errorless trials to recite the 1st 12 or 18 responses in a pattern based on Base 3. In Exp I, the pattern was presented as letters (w, d, r, dw, dd,?.?.?.) or as numerals (0, 1, 2, 10, 11,?.?.?.). In Exps II and III, the pattern was presented as letters, and Ss were given a letter-to-digit conversion list (w?=?0, d?=?1, r?=?2) either before or after learning. On a posttest, Ss who knew that the pattern related to numerals during learning performed better on transfer tasks such as addition or further counting in Base 3. Results suggest that different rule systems were acquired even though the same levels of performance on the behavioral objective were achieved. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Taking a bright view of negative priming in the light of dim stimuli: Further evidence for memory confusion during episodic retrieval.

A same–different letter-matching task was used to examine the effects of stimulus intensity on negative priming, which is poorer performance when target letters have been presented as distractor letters on the immediately preceding trial. In Exp 1, with 68 college students, stimulus intensity was manipulated between-participants, whereas in Exp 2, with 32 college students, it varied randomly from trial-to-trial within-participants. In Exp 1, negative priming was equivalent for both stimulus intensities. In Exp 2, negative priming effects were larger for repeated intensity stimuli than for nonrepeated intensity stimuli, when stimulus intensity was dim. Furthermore, for repeated intensity stimuli, negative priming effects were enhanced when the overt response required to the stimulus was repeated from prime to probe trial. These results are consistent with the hypothesis that negative priming may be due to memory confusion, rather than to inhibition of the distractor stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reading ability and single-letter orthographic redundancy.

Two experiments investigated the role of one form of intraword orthographic redundancy: the characteristic asymmetric spatial distributions of letters of the alphabet across serial positions within words. In Exp I, 81 college students demonstrated recognition knowledge of these distributions when given only the letter name, word length, and serial position information with no other context. Ss were correct more often for those letters which are least variable across serial positions. In Exp II, 28 5th graders who were skilled readers demonstrated a sensitivity to letter positional distributions similar to that of the adults; 20 poor readers did not. However, performance was equivalent for both good and poor readers on a subset of letters relatively unpredictable with respect to serial position. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processing nominal information during visual search.

Conducted 3 experiments to examine the processing of nominal information during a visual search. In Exp I, 6 experienced and 2 naive Ss searched for a single pre-specified target letter, and the stimulus exposure-time needed to yield a 50% (corrected for chance) level of accuracy was estimated using the parameter estimation by sequential testing procedure. Results show that the exposure-time was not influenced by the presence (in the irrelevant items) of the target's other case; this suggested that there was no obligatory accessing of nominal information during preattentive processing. In Exp II, 6 experienced Ss searched in Condition 1 for a single target which was specified as being one of a same-name pair of letters, and in Condition 2 for a target specified as one of a same-shape pair of letters. The exposure-time required for the same-name search was greater than that required for the same-shape search. In Exp III, accuracy of search was compared in the same-shape and same-name conditions with a control condition. The target in this control condition was specified as one of a pair of letters not sharing a name or any special shape. 12 Ss searched 6-item displays and 12 Ss searched 12-item displays for a pre-specified target letter. Results confirm the difference detected in Exp II, but they do not show any difference between performance in the same-name condition and in the control condition. It is suggested that some focal processing is required for the development of a sufficiently detailed level of visual representation to allow for naming. (French summary) (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Training behavioral consultants: A competency-based model to teach interview skills.

Developed a training package to teach consultation interview skills in 3 phases of behavioral consultation: (a) problem identification, (b) problem analysis, and (c) treatment evaluation. In Exp 1, 4 graduate students were exposed to a training manual and viewed videotape interview models. In Exp 2 with 3 graduate students, the videotapes were not used, but all other components remained intact. Exp 3 used the training manual to teach the skills to 2 practicing school psychologists, who then used the interview guidelines and format presented in the manual in an actual case in their schools. Results indicate that training specific consultation skills can be achieved successfully using standardized training procedures and formal interview guides. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of behavioral deficits caused by lesions in septal and ventromedial hypothalamic areas of female rats.

41 female Holtzman rats with lesions in ventromedial hypothalamic (VMH) area and 37 Ss with lesions in septal area were compared with 30 normal Ss for passive-avoidance performance (Exp I), reversal learning (Exp II), and spontaneous alternation (Exp III). Lesions in both septal and VMH areas produced a deficit in passive-avoidance performance, a greater number of errors in reversal learning, and reduced spontaneous alternation in a -maze. The qualitatively similar behavioral deficits produced by septal and VMH lesions suggests that at least part of the functions of both of these areas may overlap in a single system. An attempt was made to identify such a functional system, and an explanation for the behavioral deficits produced by VMH damage was offered. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social identification effects in group polarization.

Tested a model of group polarization derived from social identity theory, proposing that if group members conform to group norms, attitude polarization could occur only if group members perceive those norms as more extreme than they "objectively" are. In Exp I, 60 undergraduates perceived attitude-relevant information attributed to speakers who were categorized as a group as representing a more extreme position of the issue than when the same information was attributed to noncategorized individuals. Attitude polarization occurred when Ss believed the information came from their in-group. As predicted, this polarization resulted from Ss' adoption of the "extremitized" in-group norm. In Exp II, categorization was manipulated by focusing 42 Ss on their group performance or on their individual performance. When Ss were focused on their group membership, group norms were perceived as more extreme, and attitude polarization due to conformity to these extremitized norms occurred. When Ss were focused on their individual performance, no extremitization occurred, and attitudes shifted to a more neutral position on the issue. (34 ref) (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Make today count: A collaborative model for professionals and self-help groups.

Presents a narrative report of a field study in which members of a self-help research team provided services of significant, positive impact to one chapter of Make Today Count, a self-help group composed of cancer patients, their spouses, and health care professionals. A collaborative model is formulated. Important elements of this model include adequate knowledge of self-help processes, enhancement of rapport through acceptance of the group, and adoption of a consultive approach. Nonproductive modes on interaction observed between other professionals and chapter members are discussed. The present results are contrasted with negative results reported previously by professionals who attempted to collaborate with a similar self-help population, but who applied a different model. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some aspects of preference between immediate and delayed periods of reinforcement.

Two studies, with 6 homing pigeons, investigated an analog of the usual self-control paradigm by investigating choice between differently delayed reinforcer rates. Ss were trained on a concurrent-chain schedule in which the initial links (ILs) were equal VI schedules. The immediate terminal link (TL) consisted of an immediate 30-sec access to a VI schedule of food reinforcers, followed by a 30-sec blackout. The delayed TL consisted of an immediate 30-sec blackout followed by a 30-sec access to a VI food reinforcer schedule. Exp I comprised 3 parts, in each of which the TL VI schedules were varied. In Exp Ia, the IL responses that produced entries into both TLs were additionally reinforced with food; in Exp Ib, only the IL responses that produced entries into the delayed TL were additionally reinforced with food; and in Exp Ic, none of the IL responses that produced TL entries were additionally reinforced. When no TL entry responses were reinforced, IL response allocation was highly sensitive to variations in the TL schedules. Reinforcing entries into the delayed TLs (Exp Ib) decreased this sensitivity, and reinforcing entries into both TLs (Exp Ia) completely eliminated differential control by the TL reinforcer rates. Exp II varied the frequency of reinforcers for entries into the delayed TL and showed that even infrequent reinforcers strongly affected IL behavior allocation. Results are consistent with theories in which reinforcer value is a function of the summation of individual delays to reinforcing events. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Converging evidence for automatic perceptual processing in visual search.

Two experiments with 16 university students examined visual search performance both by itself and in conjunction with concurrent, nonvisual activity to assess the involvement of attention in the array size effect. Short-term retention was the concurrent activity in Exp I, and changing stimulus-response mapping during search was the activity in Exp II. In both experiments reaction time increased with array size (4, 8, or 12 letters) and concurrent activity, but their effects were additive. Results are interpreted as confirming predictions derived from unlimited-capacity theories of visual search and are related to findings with similar procedures in the memory search paradigm. (French summary) (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of social anxiousness in group brainstorming.

The authors predicted that individuals high in dispositional anxiousness would perform poorly when brainstorming in groups but not during solitary brainstorming. Exp demonstrated this result in a comparison of groups of 4 that were all high or all low in interaction anxiousness. In groups with 2 low- and 2 high-anxious individuals, the low-anxious individuals lowered their performance in the direction of the high-anxious individuals. These results suggest that part of the productivity loss observed in interactive brainstorming groups may be due to the inhibited performance of individuals who are uncomfortable with group interaction. Moreover, these individuals may influence others in the group to lower their performance in line with that inhibited performance level. Exp 2 demonstrated that poor performance of socially anxious groups in interactive brainstorming is not dependent on whether group members have individual microphones or share 1 common microphone. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dear Sheila: An experimental study of the effectiveness of written communication as a form of psychotherapy.

42 college students who responded to an announcement for a writing therapy study were randomly assigned to 1 of 3 groups. The writing therapy group wrote letters describing their problems to a psychotherapist whose written replies contained behaviorally oriented responses. Reassuring responses were written to the problem letters of Ss in a reassurance control group. A 2nd control group was asked to count the frequency of occurrence of specific problem behaviors and mail them to the therapist, who did not reply. 10 Ss in the writing therapy group and 8 in each of the control groups completed the 4-mo treatment period. The decrease in the number of problems (as measured by the Mooney Problem Check List) was significantly greater in the writing therapy group than in the 2 control groups. Analysis of demographic data revealed that more males than females dropped out of the study, and a significantly greater proportion of the dropouts were from lower-class families. It is concluded that writing therapy may be useful and appeal to students who do not feel able to use traditional student counseling services. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chunks are not enough: The insufficiency of feature frequency-based explanations of artificial grammar learning.

Two experiments with a total of 104 undergraduates tested chunk frequency explanations of artificial grammar learning, which hold that classification performance is dependent on some metric derived from the frequency with which certain features occur within the letter string stimuli. Exp 1 revealed that classification performance was affected by close graphemic similarity between specific training (e.g., MXRVXT) and test strings (e.g., MXRMXT), despite the fact that similar strings did not contain frequently occurring features (e.g., bigrams or trigrams). This effect was replicated in Exp 2a, and Exp 2b demonstrated that substituting letters to make the consonant strings pronounceable (e.g., substituting X, R, and T, in the consonant string MXRMXT with Y, A, I, to produce MYAMYI) affected classification performance, despite the fact that objective measures of feature frequency were not altered. It is argued that models of classification that focus entirely on the frequency of features within the literal stimulus are insufficient, and that some allowance must be made for how the stimulus is encoded. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Paleostriatal lesions in the pigeon (Columba livia) potentiate classical conditioning: Evidence from fixed-interval responding, free operant go–no-go discrimination, and alternation.

Explored the existence of behavioral deficits in the paleostriatum augmentatum in 4 experiments in which pigeons were given bilateral electrolytic lesions. Exp I, conducted with 16 Ss, investigated the effects of lesions on keypecking for reinforcement on a 1-min FI schedule. The lesions increased total response rates, but response timing was not disrupted in paleostriatal Ss. In Exp II, 17 naive Ss were given VI baseline training and, in contrast to the results of Exp I, paleostriatal lesions did not increase responding. Go–no-go discrimination, which followed baseline training, revealed enhanced positive behavioral contrast in paleostriatal Ss, which was explained in terms of additivity theory. The results of Exps I and II suggest that potentiated classical conditioning occurred in paleostriatal Ss. In Exp III, 16 naive Ss were given spatial alternation training, and performance was temporarily impaired following paleostriatal lesions. The same paleostriatal Ss showed superior differentiation performance in Exp IV with a classical go–no-go alternation procedure (which also suggested potentiated classical conditioning). It is argued that disruption of (irrelevant) response-produced information may account for paleostriatal superiority. (55 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)