Attentional scanning and space errors

Using the method of paired comparisons, pairs of simultaneous horizontal or vertical lines, with one line above and one below or one on the left and one on the right of a fixation point, respectively, were presented tachistoscopically for length comparison. Space errors were found to have a pattern similar to that of time errors. The tendency to guess the comparative response from the absolute magnitude of stimuli is proposed as a basis for time and space errors. Manipulation of attentional scanning, which implies a more frequent usage of this guessing strategy for one of the two lines in a pair, was shown to affect space errors.     

Note on Eugenio Rignano as a forerunner of the “new look” theory of visual perception

This note examines the theoretical study of perception presented by Eugenio Rignano, the Italian philosopher and editor of Scientia. Rignano's theory, which is structured around the concept of “affective tendency,” is seen as a forerunner to the “New Look” theory of perception presented by Gardner Murphy. It is concluded that the case of Rignano and Murphy is another example strengthening Henle's thesis that the study of the history of psychology can help to avoid the conceptual errors of a previously stated theory.     

Remembering changes: repetition effects in face recollection.

Two experiments examined effects of repetition and change on states of awareness in face recognition. Participants studied repeatedly presented photographs of faces, with the second presentation following either immediately after the first presentation (massed repetition) or following six intervening items (spaced repetition). To manipulate perceptual change, each repeated face was either identical or a mirror image of the first presentation. Subsequently, when recognising a face, participants indicated whether they consciously recollected its prior occurrence ("remembering") or recognised it on the basis of familiarity ("knowing"). Changes in appearance between repeated faces enhanced remember, but not know, responses, and these effects were accentuated for spaced, rather than massed, repetition. These findings suggest that distinctiveness of encoding supports the phenomenological experience of conscious remembering.     

Aging and effect of predictability on reality monitoring

This study compared the direction of source confusions and the effect of predictability on reality monitoring for internally generated information and externally derived information in younger (mean age 19-25) and older (mean age 70-85) adults. Participants were invited to listen to the conclusions of simple stories or to generate and imagine them. Conclusions could be either highly predictable (Experiment 1) or unpredictable (Experiment 2). The change in predictability produced changes in the direction of source confusions only in older adults. When a story ended in a predictable way, older adults attributed to imagination conclusions that were actually perceived, whereas the pattern of confusions tended to reverse with unpredictable stories.     

Effects of algebraic and absolute luminance differences on achromatic surface grouping

The algebraic luminance difference corresponding to a uniform achromatic surface on a uniform achromatic background determines the dark or light quality and the extent of this quality in the achromatic colour of the surface, while the absolute value of this difference determines the amount of perceived contrast between the achromatic colours of the surface and of the background. The results of an experiment designed to test whether grouping of achromatic surfaces depends on one or on both of these differences are here reported. Grouping was found to depend prevailingly on algebraic luminance difference in some subjects, prevailingly on absolute luminance differences in other subjects, and on both of these differences with similar probabilities in still other subjects.     

Forgetting curves in long-term memory: evidence for a multistage model of retention.

An experimental study with 20 normal healthy young adult subjects was performed to evaluate the interaction of type of memory tasks, type of learning modalities, and length of acquisition/recall interval. Four different tasks were employed (serial learning, paired learning, rote learning, and visuolinguistic transfer), some requiring a single trial learning modality others a multitrial learning modality. Acquisition/recall intervals were immediate, intermediate (3 min), and delayed. The experimental design allowed for the comparison of effects from five different delayed recall intervals (2, 8, 12, 24, and 48 hr). Results demonstrated a specific interaction on learning rates due to different ceiling effects for the different types of memory tasks. Forgetting rates, on the other hand, demonstrated a specific effect due to type of memory tasks and learning modalities only for differences between immediate and intermediate recall. These differences remained stable during the longer intervals and were not affected by length of interval. A multistage composition of long-term retention was suggested to explain these results, and a practical indication to build experimental procedures to study memory in the clinical field was evidenced.     

Grouping by achromatic color and surface segregation

The study explored the achromatic-color determinants of grouping of uniform surfaces. The stimuli were a set of separate uniform achromatic disks on either a uniform or a bipartite achromatic background. The participants rated the salience of grouping of these disks for different combinations of stimulus luminances. The results show that achromatic color similarity alone could not sufficiently explain the pattern of obtained factorial curves but this factor coupled with the factor of surface segregation could. Luminance contrast similarity per se was found to be unimportant for grouping.