The translation effect in memory search

The function relating recognition reaction time to the size of a memorized set of items is steeper when the memorized items and the probe are in two different categories, related by a memorized translation scheme, than when they are in the same category. Experiment 1 demonstrates that this “translation effect” is obtained for both familiar and unfamiliar translation schemes and further demonstrates that the zero-intercepts of the functions are lower when the probe differs from the memorized items in category than when it does not. Experiment 2 demonstrates that the slopes of the functions relating negative RT to memorized set size when probe and set are the same in category are steeper than the slopes of the corresponding positive functions just in case subjects are aware that the probe and set categories may differ. Experiment 3 demonstrates that the translations between memorized items and a probe that differ in category are done during the rehearsal of the memorized set, not after the probe is presented. Arguments are presented that rehearsal strategy determines memory comparison time, presumably through a hypothetical memory strength variable, but that direct-access strength theories that deny a memory scanning process are inadequate to account for the data.     

Stochastic PERT networks as models of cognition: Derivation of the mean,variance, and distribution of reaction time using Order-of-Processing (OP) diagrams

It is frequently assumed that the mental activity which leads to a given response is made up of separable components or processes. One or more of the processes are assumed to contribute to the time required to respond. Computation of the mean, variance, and distribution of the reaction time is relatively straightforward when all processes are arranged in series or parallel. However, such is not the case when the processes have complex arrangements. A solution to a useful special case of the above problem is proposed. Specifically, it is shown that simple computations yield closed form expressions for the mean, variance, and distribution of reaction time when the processes can be arranged in a stochastic PERT network and when the durations of individual processes are sums of mutually independent, exponentially distributed random variables. The method of solution relies on the construction of an Order-of-Processing (OP) diagram from the original PERT network representation of behavior.     

Prosopagnosia and visual object agnosia: A behavioral study

A left-handed woman developed visual object agnosia, prosopagnosia, and visual disorientation after resection of the right occipital lobe. Color agnosia and alexia were absent. When asked to identify objects presented visually, the patient's errors represented visually related objects (underspecifications) or perseverations. Identification was facilitated when she observed the object being used in a natural way. Identification was impaired by surrounding the object with unrelated objects, decreasing the background illumination, decreasing the duration of exposure of the object to the patient, and probably also by decreasing the visual angle subtended by the object. In addition, there were disturbances of visualization (i.e., imaging in the absence of a visual stimulus) that paralleled the perceptual difficulties. We conclude that: (1) A deficit in visual perception, characterized by insufficient feature analysis of visual stimuli, was the basis of the visual agnosia in this case. (2) The visual agnosia could not be explained by (a) a vision-language disconnection syndrome, (b) decay of visual memory traces, or (c) deficiencies in the visual fields (pathologic Funktionswandel). (3) The ability to visualize (visual imagery) probably utilizes some of the same neural pathways used in perception. (4) The results in this case probably can be generalized to some but not all cases of visual agnosia; in particular, the deficit in most previously reported patients with prosopagnosia is similar to that of our case. However, agnosic alexia and color agnosia usually have a different neuropsychological basis.     

Influence of aging on recovery from aphasia in polyglots

We analyzed patterns of recovery, according to the rules of Pitres [1895, Revue de Medecine (Paris), 15, 873–899] and Ribot (1881, Les Maladies de la Memoire, Paris: Libraire Germer Baillere et Cie, pp. 146–147), in polyglot aphasics divided into subgroups by age. The rule of Ribot did not apply predictably for any age group. Pitres' rule clearly applied, but only for the nonelderly groups. Aging and its concomitant deterioration of recent memory seem to influence patterns of recovery from aphasia in polyglots.     

The patterns of silence: Performance structures in sentence production

The pauses produced by speakers while reading familiar material were used to obtain hierarchical sentence structures. Identical structures were obtained from parsing, indicating that the performance structures of sentences are not task specific. The linguistic surface structure of a sentence is a good predictor of the pause durations. However, speakers also revealed a tendency to place pauses between segments of equal length. A simple cyclical model combining, for each pause location, an index of linguistic complexity and a measure of the distance to the midpoint of the segment, accounts for 72% of the pause time variance as opposed to 56% for the linguistic index alone. The generality of the model is shown by its good prediction of the pause durations obtained in unrelated studies in English and American Sign Language.     

Moral cognition and moral action: A theoretical perspective

Considerable theoretical work has been done in the area of moral reasoning. However, little conceptual thinking has been done about the relations between moral cognition and moral action. As a result, empirical research in this area has been unsystematic and difficult to interpret. A theoretical model, the Self Model, is proposed here, starting from the assumption that moral reasons are functionally related to action. First, a concept of cognitive motivation is presented as necessary for any cognitive account of morality. Two cognitive approaches to moral conduct, Piaget's and Haan's, are then discussed in their positive contributions and in their limitations. The Self Model is finally described through a set of empirically testable propositions. Its major theoretical characteristics are: it is cognitive, recognizing as the central function of human cognition the appraisal of truth; it acknowledges a basic duality of motivation, but stresses the normative pull of cognitive motivation; it is developmental; it uses the self as the central explanatory concept, establishing both the sense of personal responsibility and the dynamism of self-consistency.     

Another psychobiological view of sexual differentiation

The major psychobiological theory of sex differences is based on the hypothesis that hormones induce sex differences in neural organization. Hormonally masculinized or feminized brains are thought to underlie subsequent behavioral sex differences. This theory and the constructs, arguments, and evidence used in its support are closely examined. Some conceptual problems with widely used arguments are identified and discussed. Behavioral, physiological, and anatomical evidence from studies of animal sexual behavior is reviewed. It is concluded that the evidence fails to support generally accepted views that early hormones affect behavior through direct effects on brain differentiation and that behavioral differences must be located in the brain. It is argued instead that hormones coact and interact with other factors throughout development, that brain differences may result from as well as cause functional differences, and that hormone-based sources of sex differences may be located throughout the body and in the social surround. Directions for new research are suggested and implications for interpretation of human sex differences are discussed.