Area and the Intensity-Time Relation in the Peripheral Retina

Graham, C. H.; Margaria, R

doi:10.1152/ajplegacy.1935.113.2.299

Cited by 179 publications

(76 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Below critical duration the same visual effect may be produced for the absolute threshold (4,8), differential threshold (6), grating acuity (5, 15), and span of attention (10) provided the product of intensity and time (i.e., the total energy) remains constant. This reciprocal relation, the Bunsen-Roscoe law, means for the indicated visual measures reduction of exposure time is equivalent, below critical duration, to reduction of luminance.…”

Section: Discussionmentioning

confidence: 88%

See 1 more Smart Citation

Time and intensity as determiners of perceived shape.

Leibowitz¹,

Bourne²

1956

Journal of Experimental Psychology

View full text Add to dashboard Cite

It has been demonstrated that a round object viewed obliquely is matched with ellipses which are more circular than would be predicted from geometrical optics (16). Such data are examples of the tendency toward "shape constancy," a theoretical condition in which perceived circularity is constant independent of the angle of regard and the corresponding retinal image pattern. Various factors have been shown to affect the extent to which shape constancy occurs. (For a review, see Graham,7.) The duration of exposure of the test object is particularly critical; an exposure duration of .01 sec. destroys the tendency towards constancy and produces matches which are in good agreement with the shape of the retinal image (13).The purpose of the present study is to analyze the role of exposure duration and luminance as determiners of the extent to which constancy occurs. To this end, the functional relation between the matched shape of an obliquely viewed disc and the exposure duration is determined. The effect of luminance is investigated in view of the reciprocal relation between exposure time and luminance below the critical duration of about .1 sec. (3,4,5,6,8,10,11,15) and the general importance of luminance as a variable in vision. The results indicate that an exposure longer than the critical duration is required for 1

show abstract

Section: Discussionmentioning

confidence: 88%

“…These functions increase rapidly at first, and then more slowly, before approaching a limiting value. 4. The diminution of the tendency toward perceptual constancy resulting from 'reduction of luminance is attributed to the impairment of visual acuity and intensity discrimination for the "additional" stimuli in the visual field.…”

Section: Discussionmentioning

confidence: 99%

Time and intensity as determiners of perceived shape.

Leibowitz¹,

Bourne²

1956

Journal of Experimental Psychology

View full text Add to dashboard Cite

show abstract

“…[67][68][69][70][71][72][73][74] In contrast, for foveal cone vision, Riccò's area holds only up to between 2-8 min of arc 72,75,76 and does not seem to change much with light adaptation (see Chen et al 77 ). Likewise, depending upon stimulus configuration and retinal eccentricity, Bloch's Law of total temporal summation is valid up to 200-270 ms for fully dark-adapted peripheral rod vision, decreasing with light adaptation to ϳ100 ms. 68,72,[78][79][80][81][82][83] In contrast, for dark-adapted foveal cone vision, Bloch's Law holds up to ϳ100 ms, decreasing with light adaptation to 30-60 ms. 68,81,[83][84][85][86] Larger spatial and longer temporal summation for rod vision will result in severe low-pass filtering of the input signal, both in the temporal and in the spatial domain. This will reduce the responses of EMD's with a short distance and a short time delay between their two receptive fields or, equivalently, EMD's highly sensitive to high spatial and high temporal frequencies.…”

Section: A Comparison With Isoluminant Stimulimentioning

confidence: 99%

Motion perception at scotopic light levels

2000

View full text Add to dashboard Cite

Although the spatial and temporal properties of rod-mediated vision have been extensively characterized, little is known about scotopic motion perception. To provide such information, we determined thresholds for the detection and identification of the direction of motion of sinusoidal grating patches moving at speeds from 1 to 32 deg/s, under scotopic light levels, in four different types of observers: three normals, a rod monochromat (who lacks all cone vision), an S-cone monochromat (who lacks M-and L-cone vision), and four deuteranopes (who lack M-cone vision). The deuteranopes, whose motion perception does not differ from that of normals, allowed us to measure rod and L-cone thresholds under silent substitution conditions and to compare directly the perceived velocity for moving stimuli detected by either rod or cone vision at the same light level. We find, for rod as for cone vision, that the direction of motion can be reliably identified very near to detection threshold. In contrast, the perceived velocity of rod-mediated stimuli is reduced by approximately 20% relative to conemediated stimuli at temporal frequencies below 4 Hz and at all intensity levels investigated (0.92 to Ϫ1.12 log cd m Ϫ2 ). Most likely, the difference in velocity perception is distal in origin because rod and cone signals converge in the retina and further processing of their combined signals in the visual cortex is presumably identical. To account for the difference, we propose a model of velocity, in which the greater temporal averaging of rod signals in the retina leads to an attenuation of the motion signal in the detectors tuned to high velocities.

show abstract

“…This is in notable contrast to brightness perception. Barlow (1958) and Graham and Margaria (1935), for example, found that temporal integration has a longer duration when the stimulus area is small than when it is large. In other words, the critical duration of temporal integration increases with decreasing stimulus area.…”

Section: Separation In MMmentioning

confidence: 99%

Temporal and spatial integration for electrocutaneous stimulation

Higashiyama

Tashiro

1983

Perception & Psychophysics

View full text Add to dashboard Cite

Three experiments investigated the properties of temporal and spatial integration for electrocutaneous stimulation at absolute threshold level. The duration of pulses delivered to the skin were varied from .1 to 100 msec, and the spatial distribution of stimulation was varied by controlling separation, width, and length of electrodes. For temporal integration, the threshold currents were fitted by the equation (1-1 0 ) , t n = c, indicating that partial integration took place below the critical duration of 1 msec and that the integration index remained constant (n = .43) independent of the spatial distribution of stimulation. For spatial integration, the separation of electrodes was found to be the most effective determiner of threshold current. Furthermore, when the equation (1-1 0 ) • Am = k was fitted to the spatial integration data, the value m resulted in 1.33 with a critical separation of 8 rom, which was constant for any pulse duration.properties of temporal integration, therefore, it was necessary to confirm the previous findings by using different types of electrodes.In the studies of vision, touch, and hearing, the equationThe present study deals with temporal and spatial integration for electrocutaneous stimulation at absolute threshold level. Babkoff, Brandeis, and Bergman (1975), Hahn (1958), Rollman (1969, 1975), and Uttal (1958 showed how threshold varies with pulse duration and obtained the psychophysical .hyperbolic function:

show abstract

Area and the Intensity-Time Relation in the Peripheral Retina

Cited by 179 publications

References 0 publications

Time and intensity as determiners of perceived shape.

Time and intensity as determiners of perceived shape.

Motion perception at scotopic light levels

Temporal and spatial integration for electrocutaneous stimulation

Contact Info

Product

Resources

About