A perceptual phenomenon and its neurophysiological correlate.

A square-wave grating from which the fundamental harmonic has been subtracted (missing fundamental grating) when viewed from a suitable distance appears similar to another grating of periodicity three times higher. The neurons of the visual cortex of the cat, in a given range of spatial frequencies characteristic of each cell, give similar responses to the two gratings.     

A Survey of Patients’ Experiences with the Cancer Genetic Counseling Process: Recommendations for Cancer Genetics Programs

In order to promote ongoing quality improvement of not only the Penn State Cancer Genetics Program, but also other cancer risk assessment programs throughout the country, we developed, piloted and conducted a survey to explore patient expectations, experiences, and satisfaction with the cancer genetic counseling process. The comprehensive survey was mailed to 340 eligible patients, 156 (45.9%) of whom returned the completed survey within the allotted time. Responses to closed-ended questions were tallied and open-ended questions were content analyzed. Major findings show that: (1) Patients were seeking cancer-related information and support throughout the cancer risk assessment process and were interested in participating in available research studies; (2) The setting in which patients are seen for cancer risk assessment may pose potential emotional ramifications; (3) Misperceptions regarding insurance discrimination and lack of insurance coverage persist; (4) Patients view the genetic counselor as responsible for updating them about new discoveries. Specific recommendations for cancer genetics programs are included.     

Recognition of positive and negative bandpass-filtered images

A study is reported in which the significance for vision of low- and high-spatial-frequency components of photographic positive and negative images was investigated by measuring recognition of bandpass-filtered photographs of faces. The results show that a 1.5 octave bandpass-filtered image contains sufficient visual information for good recognition performance, provided the filter is centred close to 20 cycles facewidth-1. At low spatial frequencies negatives are more difficult to recognize than positives, but at high spatial frequencies there is no difference in recognition, implying that it is the low-frequency components of negatives which present difficulties for the visual system.     

Saccades compress space, time and number

It has been suggested that space, time and number are represented on a common subjective scale. Saccadic eye movements provide a fascinating test. Saccades compress the perceived magnitude of spatial separations and temporal intervals to approximately half of their true value. The question arises as to whether saccades also compress number. They do, and compression follows a very similar time course for all three attributes: it is maximal at saccadic onset and decreases to veridicality within a window of approximately 50ms. These results reinforce the suggestion of a common perceptual metric, which is probably mediated by the intraparietal cortex; they further suggest that before each saccade the common metric for all three is reset, possibly to pave the way for a fresh analysis of the post-saccadic situation.