A DEVELOPMENTAL DEFICIT IN LOCALIZING OBJECTS FROM VISION

Abstract— We describe a college student, A. H., with a developmental deficit in determining the location of objects from vision. The deficit is selective in that (a) localization from auditory or tactile information is intact, (b) A H reports the identity of mislocalized objects accurately, (c) visual localization errors preserve certain parameters of the target location, and (d) visual localization is severely impaired under certain stimulus conditions, but nearly intact under other conditions. These results bear on the representation and processing of location information in the visual system, and also have implications for understanding developmental dyslexia.     

On the naming of color words and color patches

Subjects can name color words faster than they can name color patches. To account for that effect, a generic model of naming is described which assumes that words access the mental lexicon directly, whereas color patches do so only indirectly via an initial imaginal or semantic representation. However, Lund (1927) reported that the naming advantage for words disappeared when all the items to be named on a page were the same (i.e., they were blocked). In the present study, three experiments are reported that were designed to provide a clearer empirical definition of Lund’s blocking effect and to ascertain the extent to which it requires a modification of the generic model. The blocked lists had 50 items arranged into 10 blocks, with each block homogeneous with respect to color. The block lengths were either all a predictable length of 5 items or they varied randomly from 1 to 9 items. The data indicated the following: (1) The blocking effect occurred even when the task required a full identification of each item, and (2) the blocking effect was confined to within-block transitions. Blocking seemed to eliminate the word advantage by allowing the subject to re-use the lexical entry used for the immediately prior item, which is consistent with the generic model.     

The effect of token reinforcement on McCarthy Scale performance for white preschoolers of low and high social position

In Study 1, the effect of making tokens contingent on correct performance of low social position preschoolers on the McCarthy Scales of Children's Abilitieswas examined. Preschoolers in a token reinforcement group scored significantly higher (mean=8 IQ points) than subjects in a control group. In Study 2, the effect of tokens on McCarthyresults was examined as a function of social position in a 2×2 design. The high social position control group scored significantly above the low social position control. The low social position token reinforcement group, however, performed as well as both the high social position control and token reinforcement groups. Use of systematic reinforcement contingencies to reduce test error is discussed.     

A study of neuropsychological impairment among school-indentified learning-disabled students

This investigation examined the proportion of school-identified learning-disabled (LD) students who scored in the impaired range on the Halstead Reitan Neuropsychological Battery for Children (HNBC) over a 20-year period. A difference was noted in findings for periods before and after the passage of federal legislation (Public Law 94-142); specifically, the proportion of LD students who scored in the impaired range on neuropsychological tests was significantly higher prior to than after this law. A similar pattern of impaired performance across the different tests was noted before and after the legislation. The implications of these results for theorists and practitioners are discussed.     

Intelligence and the Frontal Lobe: The Organization of Goal-Directed Behavior

Basic to the study of individual differences is the concept of “general intelligence” or Spearman'sg.In this article we suggest thatgis largely a reflection of the control functions of the frontal lobe. A series of experiments investigates a phenomenon we callgoal neglect:disregard of a task requirement even though it has been understood and remembered. Subjectively it is as though the neglected requirement “slips the subject's mind.” Previously described in frontal patients, we show that goal neglect can also be seen in some members of the normal population. In line with conventional distinctions between controlled and automatic processing, eliciting conditions for goal neglect include novelty, weak error feedback, and multiple concurrent task requirements. Under these conditions neglect is linked closely togand extremely common after frontal lesions. Following many other models, we suggest that behavior in any task is structured by a set of action constraints or requirements, derived in part from verbal instructions and specified at multiple levels of abstraction. A frontal process of constraint or requirement activation is fundamental to Spearman'sg.     

Expressing a Good Will: Kant on the Motive of Duty

If any action is to be morally good it is not enough that it should conform to the moral law-it must also be done for the sake of the moral law: where this is not so, the conformity is only too contingent and precarious, since the nonmoral ground at work will now and then produce actions which accord with the law, but very often actions which transgress it.     

Predictors of Developmental Task Attainment for Young Adults from Divorced Families

To determine which variables impact developmental task attainment for young adults from divorced families, respondents completed demographic questions, the young adult version of the Personal Authority in the Family System Questionnaire, and the three family relationship subscales of the Family Environment Scale. Of the factors assessed, results suggest that the quality of post-divorce family functioning is the most salient predictor of development for young adults from divorced families. Additionally, although conflict and cohesion have unique effects on task attainment for young adults, expressiveness appears to be the dimension of post divorce family functioning most related to young adult development.     

Immediately preceding stimuli increase the detection of a less detectable but not a more detectable stimulus

Both a small (S) and a large (L) stimulus occurred individually and randomly over trials. The task was to make the same speeded response to either stimulus. LSSS sequences on trials N-3, N-2, N-1, and N, respectively, resulted in a faster RT to S on trial N than to S on trial N-2. However, SLLL sequences did not produce a corresponding increase in detection. Also, overall, S was less detectable than L. Suppose that the physical S on trial N was lower in detectability-memorability than a memorial S produced by S on the immediately preceding trials N-1 and N-2. If so, the physical S may have assimilated in detectability-memorability to the memorial S, explaining why its detectability increased. In contrast, the physical L may have been sufficiently high in detectability-memorability to preclude a comparable assimilation. The theory: assimilation underlies detectability, regardless of whether two components are both physical (previous research), or whether one is physical and the other is memorial (the present research).     

A comparison of multiple versus single examples of the correct stimulus on task acquisition and generalization by persons with developmental disabilities

In teaching discriminations to persons with retardation, we often presume we will improve acquisition and generalization if we use multiple examples of boththe correct and incorrect stimuli. Two experiments were conducted to test this hypothesis. In the first experiment, 7 persons with moderate retardation learned to discriminate between functional words under two conditions. In one condition, Multiple Example of S- Only,1 example of the correct stimulus (S+) and 10 examples of the incorrect stimulus (S-) were used during acquisition. In the other condition, Multiple Examples of S+ and S-,10 examples of the S+ and 10 examples of the S- were used. Results showed that the condition which presented only a single example of S+ was superior 16 times and inferior 4 times during acquisition, generalization, and maintenance. A second experiment was conducted to (a) replicate the methodology and procedures in Experiment 1 with different participants, (b) determine whether the results were replicable, and (c) obtain efficiency data. Results replicated the findings of the first experiment. The condition which presented only a single example of S+ was superior on measures of (a) trials to criterion, (b) percent correct during acquisition, and (c) minutes to criterion. On measures of generalization, the two conditions were relatively equal. Thus, the condition which presented only a single example of the correct stimulus was more efficient and was just as effective in generalization as the condition which presented multiple examples of both the S+ and S-. These surprising results were discussed in terms of stimulus control, why students performed just as well during generalization when only one example of the S+ was used, why acquisition was also poorer for this condition, and how future studies might address these points.