Span of perception as related to two stimulus-report intervals

The Psychological Record -     

Temporal and spatial factors in the fading of diffuse visual images

Pattern vision breaks down after a period of inspecting a diffusely contoured dark figure upon a ground of uniform brightness and texture. When the field is illuminated with flickering light it is found that the persistence of pattern vision is inversely related to flicker frequency up to the region of fusion. At low flicker frequencies complex figures persist longer than less complex ones of equivalent area, but the reverse applies at frequencies above fusion. These findings are consistent with data obtained from experiments using stabilized retinal images     

Event perception as a control process for visual awareness

ABSTRACT

We present evidence demonstrating that the structure of everyday events guides attention to and representation of visual properties. Incidental change detection increases dramatically at the boundaries between events, whereas individuals are largely unaware of the sequence of actions within a single event. Observers demonstrate a limited capacity for representing events, and inducing cognitive load by presenting two simultaneous events decreases detection of sequence errors. These studies support emerging evidence that the event perception network operates as a control process that guides attention and awareness in real-world settings.     

Nonveridical factors of visual perception and close following on the road

Close following on the road, identified as contributing to accidents, may be partly explained as an involuntary response to nonveridical perceptual factors. These factors concern (a) underestimation of the driver's own speed and (b) incorrect estimations of the distance away and speed of the vehicle ahead of the driver.     

Semantic and imaginal factors in learning as related to age

Sixty subjects apiece from third and sixth grade populations were given a twelve-item paired-associate list to learn under either regular or imagery instructions. The paired associates were presented in sentences or phrases which represented varying degrees of semantic correspondence between study and test trials. It was found that the semantic manipulations influenced learning similarly in the two grades, while imagery instructions produced different effects at each grade level.     

Selective mechanisms in visual perception

The notion of perceptual tuning is investigated by presenting alternatives either before, after, or both before and after a tachistoscopic stimulus. Study 1 (N = 12) showed that identification accuracy is best with alternatives both before and after the stimulus, poorest with alternatives after the stimulus, and intermediate with alternatives only before the stimulus. Study 2 (N = 3) indicated that performance with alternatives both before and after the stimulus varies according to where S is permitted to fixate prior to each exposure. The possibility of a central tuning mechanism was not strongly supported.     

Processing order in visual perception

Initial increases in the availability of items for report following tachistoscopic presentation of centrally-fixated rows of seven random letters were directly evaluated by measuring report accuracy following exposure durations of 10, 20, 40, 80 and 160 ms. A partial-report technique was used, and each presentation of a letter row was immediately followed by the presentation of a masking stimulus. Each of 10 subjects received 840 trials which reflected 24 trials for each exposure-duration by position-probed combination. The letters at both ends of a row became available for report prior to the centre letters. In addition, report of the left-most letter was consistently better than report of the right-most letter, and report of the centre item at fixation improved at a more rapid rate with increased exposure duration than report of the other centre letters. This pattern of results provides support for certain components of several different previous proposals concerning the order in which individual items from multi-element displays become available for report.