Short-term visual memory in schizophrenics.

Hypothesized that the deficit of poor premorbid schizophrenics in backward masking is due to interference in short-term visual memory (STVM) because of the tendency to process a pattern mask as if it were a cognitive mask. The hypothesis was tested in a backward-masking picture-recognition paradigm, using data from 32 male psychiatric patients (aged 18–55 yrs) and 14 hospital personnel. The 12 good premorbid schizophrenics, 7 nonschizophrenic psychotics, and normal Ss all showed differential pattern- and cognitive-mask performance. The performances of 13 poor premorbids were equivalent on both mask types. Findings corroborate the hypothesis. It is suggested that integration of stimuli in poor premorbids' sensory storage was intact and that the disruption in processing caused by a pattern mask at 200–300 msec was due to an interference in STVM. It is concluded that the hypothesis of a deficit in perceptual organization best accounts for the apparent disruptions in poor premorbids' STVM. (70 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Integration of linguistic ideas in schizophrenics.

S. D. Koh and R. A. Peterson (1978) found that requiring semantic encoding at acquisition facilitated recall for schizophrenics in the same way that it does for normals. It was hypothesized that more complex forms of semantic organization would reveal a deficit in schizophrenics, but not for all subtypes. The paradigm used, developed by J. D. Bransford and J. J. Franks (1971), involves an incidental sentence recognition task in which Ss are presented interrelated parts of a complex idea in acquisition and subsequently tested for their memory of new and old (previously seen) instances of the idea. In the present study, with 56 hospitalized male veterans and 14 college students, normals' and nonpsychotics' patterns of recognition responses reflected the organization of this complex idea, even when they had actually never seen the specific test sentences. All schizophrenics were found to be capable of distinguishing sentences that violated the relations within the complex ideas from those that did not, but only the good premorbid acute patients' responses reflected the integration of part ideas. Poor premorbid acute patients showed an intermediate level of integrating semantic information, and chronic patients were unable to use the interrelations within ideas to organize their memories. (1? p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance of process schizophrenics on tasks involving visual search.

Compared the response times of 32 process schizophrenics and 16 nonhospitalized matched controls on 3 visual search tasks. Exp I involved the location of a target letter within an array of different background letters. Other experiments required a same–different response. Exp II involved the identification of a single different letter set within the uniform context of a square display formed by up to 40 replicates of another letter. Exp III presented 2 3–6 letter clusters in a single horizontal line. The 2 clusters were identical or had 1 different letter. Word and nonword clusters were used. Paranoid and nonparanoid groups did not differ on any measure. Schizophrenic response times were about 1 sec longer, but measures of rate of increase in response time with number of letters displayed did not generally differ significantly between groups. Schizophrenics tended to make more errors. Experimental manipulations affected the response times and error rates of schizophrenics and controls alike, and to much the same degree. Results suggest that process schizophrenics are not abnormally slow when extracting information from visual displays, and they appear to perform operations and strategies similar to those of normals when doing so. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Scanning time of schizophrenics and normals for visual designs.

Measured the time to locate a target design in an array of 4 designs by 12 process and 12 reactive schizophrenics and 12 hospitalized and 12 nonhospitalized normal controls. Designs and arrays differed in the size of the rotation and reflection equivalence sets from which they were selected. Differences in mean reaction time (RT) attributable to these characteristics were found as expected. Schizophrenics performed slower than the nonhospitalized normals. The mean RT of hospitalized normals, mostly spinal cord injury patients, fell between that of the process and reactive schizophrenics. No Group * Stimulus Condition interaction effects were found. Results are interpreted as not supporting leading theories of schizophrenic deficit. (21 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contrasting patterns of fantasy and motility in Irish and Italian schizophrenics.

Several hypotheses concerning differences in fantasy and motor activity of schizophrenics of Irish and Italian descent were developed on the basis of anthropological evaluation of cultural patterns and child-rearing practices. Schizophrenics of Irish descent were expected to be more given to imaginative behavior and motor control when compared with those of Italian descent. Psychological instruments used were the Rorschach, Barron's Movement-Threshold Inkblots, TAT, Porteus Mazes, tests of time estimation, motor inhibition, admission-denial of frustration, and ward behavior ratings. 60 male, veteran patients were used as Ss, one-half of Irish and one-half of Italian descent. The results appeared to support the hypothesis of persistent differences in motor and fantasy activity. Implications for review of psychiatric nosology, personality research, and interdisciplinary collaboration were suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of signal-noise similarity on visual information processing of schizophrenics.

Performed 2 studies with a total of 34 schizophrenic and 34 nonschizophrenic male inpatients to examine the effect of target-noise similarity on the span of apprehension performance of schizophrenics. Ss were required to search a briefly presented display of letters for a target letter which was presented along with noise letters of varying degrees of physical similarity to the target. In both studies the schizophrenics' performance was significantly poorer than that of controls, and the target-noise similarity manipulation affected both groups equally. Results indicate that the information-processing operations of both groups were similar but that schizophrenics performed them at a slower rate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Salience of visual patterns in the human infant.

In 3 experiments, 350 10-mo-old infants were familiarized on a simple frame containing 2 horizontally placed circles and dishabituated on a variety of transformations on the standard. Results show that transformations that increased the sizes of the circular elements or changed their spatial arrangement from horizontal to vertical produced significant increases in attention. However, changes in number of circles, shape of the internal elements, and placement outside the frame did not produce dishabituation, despite the discriminability of these changes. It is suggested that the infant may be biologically prepared to award salience to increased size and changes in the horizontal–vertical placement of elements. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit and explicit memory for visual patterns.

The article reports an investigation of implicit and explicit memory for novel, visual patterns. Implicit memory was assessed by a speeded perception task, and explicit memory by a four-alternative, forced-choice recognition task. Tests were given either immediately after testing or 7 days later. The results suggest that a single exposure of a novel, nonverbal stimulus is sufficient to establish a representation in memory that is capable of supporting long-lived perceptual priming. In contrast, recognition memory showed significant loss over the same delay. Performance measures in the two tasks showed stochastic independence on the first trial after a single exposure to each pattern. Finally, a specific occurrence of a previously studied item could be retrieved from explicit memory but did not affect the accuracy of perception in the implicit memory test. The results extend the domain of experimental dissociations between explicit and implicit memory to include novel, nonverbal stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Integration of local inputs in visual cortex

In mammalian visual cortex, local connections are ubiquitous, extensively linking adjacent neurons of all types. In this study, optical maps of intrinsic signals and responses from single neurons were obtained from the same region of cat visual cortex while the effectiveness of the local cortical circuitry was altered by focally disinhibiting neurons within a column of known orientation preference. Maps of intrinsic signals indicated that local connections provide strong and functional subthreshold inputs to neighboring columns of other orientation preferences, altering the observed orientation preference to that of the disinhibited column. However, measuring the suprathreshold response using single-cell recordings revealed only mild changes of preferred orientation over the affected region. Because strongly tuned subthreshold inputs from cortex only marginally affect the tuning of a cortical cell's output, it is concluded that local cortical inputs are integrated weakly compared to geniculate inputs. Such circuitry potentially allows for the normalization of responses across a wide range of input activity through local averaging.     

Clinical patterns of defense as revealed in visual recognition thresholds.

To test the relationship between characteristic mode of cognitive reactivity to conflict-arousing stimuli in a laboratory situation as compared with life in general, Ss (adult male hospitalized psychiatric patients between 21 and 45) were placed in one of 3 categories, which reflected characteristic modes of dealing with conflictual ideas and feelings (externalizers, internalizers, acting-outers). Ss were then presented with visual stimuli (words and pictures) geared to heighten conflict arousal; capacity for recognition was measured by the level of illumination required for identification of the stimulus. The results indicated that externalizers and acter-outer demonstrated lower thresholds of recognition for conflictarousing (sexual, aggressive, dependent) stimuli than for neutral ones, and internalizers revealed higher thresholds. No relationship was found between specific conflict area or psychiatric diagnosis and perceptual mode. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of orientation on the identification of simple visual patterns.

Two experiments, with 16 university students, revealed that errors of identification for alphanumeric characters increased approximately linearly with increased angular deviation from the standard upright orientation. Thus, pattern recognition does not seem to proceed via the extraction of "orientation-invariant features." It is argued that prior failures to discover systematic effects of orientation on the identification of simple patterns may have resulted from the use of RT as a dependent measure. Based on the data from Exp II, it was estimated that as little as 15 msec of processing time may have been sufficient to compensate fully for a 180° rotation of a simple pattern in the present experimental situation. Thus, RT experiments seeking effects of orientation must be designated to detect effects of smaller magnitude than may have been previously anticipated. (French abstract) (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual selectivity in hallucinatory schizophrenics.

Constructed a manual for categorizing themes present in hallucinations using 10 males and 7 females from 49 actively hallucinating Ss. The authors agreed on the major theme for 30 of 32 remaining Ss, indicating significant interjudge reliability (p     

A mnemonic based on arranging words on visual patterns.

Conducted 3 experiments with 264 undergraduates to demonstrate that arranging word lists on distinctive visual patterns results in better recall performance than does presenting the same word lists on a pattern that is always the same. In Exp I, lists of concrete nouns placed on different visual patterns were recalled better than those lists placed on the same pattern. This was true immediately after learning and 1 wk later. In Exp II, abstract terms taken from an introductory textbook in psychology were arranged on the same or on different drawings. When placed on the different drawings, the words were better learned, and what was learned was better retained in memory for 1 wk. In Exp III, both visual-pattern mnemonic aids and story mnemonic aids were provided to Ss for different lists. The story mnemonic was found to be superior. Possible reasons why the spatial-arrangement mnemonic and story mnemonic are effective are discussed. One important factor seems to be the discriminability among the representations of the word lists in memory. By placing words on distinctive visual patterns, this discriminability can be increased and recall performance can be enhanced. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Monocular distance perception in schizophrenics.

This study was designed to investigate the possibility of a dysfunction in monocular depth perception in schizophrenics. 50 schizophrenics and 50 normals were asked to align monocularly viewed patterned and unpatterned projected images with each of 5 monocularly viewed, minimally lighted rods. An analysis of variance indicated a difference significant beyond the 1% level in the alignment ability of the 2 groups and stimulus intensification of the images with color increased both groups' alignment ability. A trend analysis indicated a significant increase in the difference between the groups from p     

Transfer learning in chronic schizophrenics.

Compared reversal shift, where the assignment of stimuli to categories changed but the relevant dimension did not change, and extradimensional shift, where a different dimension was made relevant after training. 28 chronic schizophrenics were trained to the same consecutive correct response criterion in a 3-choice form or color discrimination and shifted to 1 of 4 possible transfer tasks. It was found that (a) extradimensional shift took more trials and errors to criterion than reversal shift, and (b) more perseveration as compared to other errors were made by the total sample. The need for a uniform methodology and an evaluation of S selection factors when investigating the performance of schizophrenics is discussed. (23 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Span of apprehension in acute schizophrenics.

Compared the span of apprehension for 2 schizophrenic groups (15 good premorbid paranoid and 15 poor premorbid nonparanoid) with the span for a normal control group (15 hospital aides) by a forced-choice letter-recognition method analogous to signal-detection methodology. This procedure, in conjunction with a quantitative model of the span, provides an indirect but relevant measure insensitive to variance imposed by nonperceptual systems. The span size was the same for all 3 groups when visual "noise" was absent. In the presence of noise, span size for both schizophrenic groups was about 50% smaller than that of the control group. It is argued that the reduction in span represents a true deficit in attention, uncontaminated by extraneous variables. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Short-term memory impairment in chronic schizophrenics.

Assessed the short-term memory capacities of 4 chronic, schizophrenic and 4 nonschizophrenic psychiatric patients who served as controls. The information to be remembered was presented both visually and verbally and was later probed for after a variable interval by either visual or verbal cues. Schizophrenics and controls did not differ with respect to which type of cue retrieved more of the information, suggesting that the modality in which the information was stored was the same for both groups. However, schizophrenics were markedly inferior to controls regarding both the initial acquisition of information and the maintenance of it in storage. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Characteristics of untestable chronic schizophrenics.

Some patients refused to be tested, and some agreed to be tested but were too confused to produce scorable answers. The untestable-refused and testable patients were seen to be more alike on demographic variables, with the untestable-confused group appearing to be made up of deteriorated patients. "The results suggest that [so-called] untestable patients do not compose a homogeneous category. Untestable patients can meaningfully be divided into at least two major subgroups according to level of ability in test performance and motivation to accept the task." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time and space orientation in schizophrenics.

The spatial and temporal orientation of a group of 50 schizophrenics is compared with a matched group of 50 normal subjects selected from attendants and applicants for attendants at the Austin State Hospital. The results show that: 1. Schizophrenic S's are significantly poorer than normals on all the space and time orientation tests except that for bodily orientation. 2. The items that differentiate the schizophrenic from the normal have in common the absence of a frame of reference in the immediate perceptual field or to require attention to and retention of complex relationships. (PsycINFO Database Record (c) 2010 APA, all rights reserved)