Daniel Landis

Some Determinants of Certitude Judgments in a Complex Decision-Making Task.

This research investigated the relationship between certitude and decision adequacy using a complex problem-solving task. 120 male college Ss, serving with pay, solved 12 problems which varied in amount of information and method of coding. Each S also estimated the adequacy of his solution as well as the affective tone of the situation after the solution of each problem. Data were also available from a set of cognitive-perceptual-style measures. Results indicated that: (1) the correlation between decision adequacy and certitude is low and probably of negligible significance; (2) certitude is closely related to affective aspects of the stimulus; and, (3) level of certitude is related to the level of cognitive and perceptual scanning employed by S. It is suggested that (1) the correlation between certitude and decision adequacy may also be a function of the extensiveness of the response repertoire permitted S in the experimental situation, and (2) more intensive examination of individual differences with respect to accuracy of certitude judgments may be necessary.

Visual Search Time in a Structured Field

The primary purpose of the present experiment was to validate in a structured field several reported relationships which have been found in separate studies using search time in unstructured visual fields. A secondary aim was to assess the effect of compressing irrelevant information on search time. 36 Ss searched for information on military-type maps differing in density, method of coding, and amount of compression. Results indicated that: (a) the relationship between density and search-time is J-shaped; (b) this relationship is primarily a function of the type of coding scheme used; and, (c) Ss insist on decoding irrelevant information. The results are sufficiently at variance with studies using unstructured fields to question the generalizability of those researches.

Effect of LSD-25 on Activity Level of the Hooded Rat

Most psychopharmacological studies investigating the behavioral effects of LSD-25 have reported a decrement in operant performance ( 2 ) . Before we can accept these results as unequivocal, however, parametric investigations of the drugs effects on behavior must be conducted across a wide range of species. In the present study we chose general activity as a response measure for it is easily adapted to work with most species and eliminates time-consuming training procedures. Ss were 1 0 adult female Long-Evans rats about 8 0 days old. The apparatus was a standard laboratory activity wheel modified to record a fifth of a revolution in either direction. Illumination was provided by a 150-w bulb, located 4 ft. above the apparatus. All Ss were placed on a 23-hr.-food-and-water deprivation schedule for 1 2 days before the experiment. Deprivation continued during the experiment. Each S received both LSD and saline solutions in a counterbalanced design. All Ss received 0.5-cc intraperitoneal injections of LSD-25 (0.1 mg/cc) and normal saline on successive days. Each S was tested for 30 min. at the same time each day. A 10-min. period in which S was housed in a cage adjacent to the activity wheel preceded the test period to allow time for the drug to cake effect. At the end of testing, S was rerurned to his home cage. Ss were fed 3 hr. later. The data were cast into a 2 X 2 Latin square, and an analysis of variance performed. Ss injected with LSD-25 produced significantly fewer revolutions than those receiving saline (F = 13.2, df = 1/17, f i < .01) . N o significant order effect was found. Thus, LSD25 had a decremental effect on general activity which agrees with other studies of operant behavior ( 3 ) . A more adequate design would include various dosages and a second control group which would have received no injections to allow evaluation of effects of injection on Ss general accivity. Although our results indicate that the measure of activity is certainly adequate for our purposes, stabilimetric measures of activity (1) may, however, prove more useful for comparative purposes.

Some Determinants of Multidimensional Points of View: Two Studies.

Two studies are reported bearing on the relationship of multidimensional points-of-view to cognitive perceptual style and complex decision-making performance. In Study I, 31 Ss scaled two sets of stimuli. Factor loadings from a points-of-view analysis were correlated with scores from 8 cognitive perceptual style measures. Sufficient significant correlations were found to warrant a more extensive study. In Study II, 120 Ss scaled 12 problem maps after solving the problems. Each S was also administered the measures used in Study I. The scaling data were subjected to a points-of-view analysis and related to the solution and style data by a stepwise multiple regression procedure. Results indicated that: (1) multidimensional points of view are related to style data; (2) points of view are also related to complex decision-making performance; and (3) some of the previously reported style groups break down into sub-groups.

Effect of Amount of Scanning from Memory on Phenomenal Size of Objects

The purpose of the present study was to investigate what happens to the phenomenal size of an object stored in memory. Fifteen adult female Ss were divided into three groups of five Ss each. Each group estimated the size of a set of circles 30 and 60 sec. after presentation. The groups differed according to the amount of memory inspection they were permitted during the delay period. Results indicated that there is no overall difference between the time limits investigated, except when there is a specific instruction to call up and inspect the object from memory. The implications of these findings for both traditional Gestalt theory and a general theory of memory were discussed.