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PubMedDate not supplied

Modality specificity of auditory and visual pattern recognition: implications for the assessment of central auditory processing disorders.

We determined the degree of overlap in required processing resources between simultaneously performed non-verbal auditory and visual pattern-recognition tasks. In experiment 1, concurrent presentation of binary auditory frequency pattern sequences interfered with recognition memory of both binary auditory sound pressure level and binary color sequences, but the amount of interference was greater with auditory-level patterns. In experiment 2, mutual interference was demonstrated between auditory level and visual color pattern sequences. We conclude that dual-task performance using auditory and visual pattern-recognition tasks is limited by modality-specific perceptual factors and by modality-independent cognitive factors not specific to a single sensory modality. It is concluded that poor performance on a single pattern-recognition task cannot be associated in a one-to-one fashion with a single perceptual ability or process.

Adult↗
PubMed2004

Visual pattern recognition in Drosophila is invariant for retinal position.

Vision relies on constancy mechanisms. Yet, these are little understood, because they are difficult to investigate in freely moving organisms. One such mechanism, translation invariance, enables organisms to recognize visual patterns independent of the region of their visual field where they had originally seen them. Tethered flies (Drosophila melanogaster) in a flight simulator can recognize visual patterns. Because their eyes are fixed in space and patterns can be displayed in defined parts of their visual field, they can be tested for translation invariance. Here, we show that flies recognize patterns at retinal positions where the patterns had not been presented before.

Animals↗
PubMed2004

Local-feature assembling in visual pattern recognition and generalization in honeybees.

Generalization is a cognitive ability that allows similar stimuli along a given dimension to be treated as equivalents. Insects exhibit high levels of visual generalization. Honeybees trained to recognize complex visual stimuli on the basis of a single feature generalize their choice to novel stimuli sharing that common feature with the trained stimuli. The demonstration of this kind of performance has been limited to the use of a single visual feature, and the possibility that bees link different features in learning a visual pattern has been denied. Here we show that honeybees trained with a series of complex patterns sharing a common layout comprising four edge orientations remember these orientations simultaneously in their appropriate positions, and generalize their response to novel stimuli that preserve the trained layout. Honeybees also generalize their response to patterns with fewer correct orientations, depending on their match with the trained layout. Stimulation of the achromatic L-photoreceptor input is necessary for this task. The mini-brain of the honeybee can thus extract regularities in its environment and establish correspondences among correlated features. It can thus generate a large set of object descriptions from a finite set of elements.

Animals↗
PubMed1982

Rotational invariance in visual pattern recognition by pigeons and humans.

Pigeons and humans chose which one of two alternative visual forms was identical to, or a mirror image of, a previously presented sample form. The two comparison forms were presented in various orientations with respect to the sample. The two species yielded similar accuracies, but although human reaction times depended linearly on the angular disparities, those of the pigeon did not. Humans appeared to apply a well-known, thoughtlike, mental rotation procedure to the problem, whereas pigeons seemed to rely on a more efficient automatic process that humans can use only in simpler rotational invariance tasks. Mirror-image forms may be better discriminated by the pigeon's visual system than by the human one.

Animals↗
PubMed1995

Visual pattern memory without shape recognition.

Visual pattern memory of Drosophila melanogaster at the torque meter is investigated by a new learning paradigm called novelty choice. In this procedure the fly is first exposed to four identical patterns presented at the wall of the cylinder surrounding it. In the test it has the choice between two pairs of patterns, a new one and one the same as the training pattern. Flies show a lasting preference for the new figure. Figures presented during training are not recognized as familiar in the test, if displayed (i) at a different height, (ii) at a different size, (iii) rotated or (iv) after contrast reversal. No special invariance mechanisms are found. A pixel-by-pixel matching process is sufficient to explain the observed data. Minor transfer effects can be explained if a graded similarity function is assumed. Recognition depends upon the overlap between the stored template and the actual image. The similarity function is best described by the ratio of the area of overlap to the area of the actual image. The similarity function is independent of the geometrical properties of the employed figures. Visual pattern memory at this basic level does not require the analysis of shape.

Animals↗
PubMed1986

Horizontal-vertical structure in the visual comparison of rigidly transformed patterns.

Visual recognition of patterns reflected or rotated through 180 degrees (point-inverted) depends critically on their positional symmetry and separation in the field. A possible explanatory scheme suggested a description of internal pattern representation structures and simple internal operations that naturally involved a horizontal-vertical reference system. Predictions of the scheme were tested here in three experiments. Subjects made same-different judgments on pairs of random-dot patterns briefly presented in various arrangements and related by reflection, point-inversion, or identity transformation, or paired at random. Experiment 1 tested reflected patterns and verified the importance of orientation of the reflection axis relative to display-configuration axis. Experiment 2 demonstrated an oblique effect of configuration on performance with reflected patterns, but not with identical or point-inverted patterns. Experiment 3 demonstrated a vertical shift effect of configuration on performance with point-inverted patterns, but not with identical or reflected patterns. We concluded that in same-different pattern comparisons, a horizontal-vertical reference system appears fundamental in determining the nature of and operations upon internal pattern representations.

Adult↗
PubMed1983

Some factors affecting tactile pattern recognition.

Tactile patterns were generated by means of a 6 X 24 array of vibrating pins. The ability of subjects to recognize these patterns presented to their fingertips was shown to be affected by a number of factors, including the display time of the pattern, the mode of generating the tactile patterns, the temporal relationship between the pattern to be identified and a masking stimulus, the type of masking stimulus, and temporal integration. Word recognition was also shown to be affected by some of these factors. Parallels are drawn between the factors that affect vibrotactile pattern recognition and visual pattern recognition.

Computers↗
PubMed1986

Recognition of visual pattern components in squirrel monkeys.

In 4 mixed-age captive groups of squirrel monkeys the predator alarm behavior control by means of visual stimuli was studied, and the extent to which socially inexperienced infant squirrel monkeys are capable of species-specific alarm behavior. By means of color film projection it was shown that both the socially experienced and inexperienced subjects recognized two-dimensional representations of real objects or situations. Behavioral reactions to visual stimulus patterns of terrestrial predators and graded controls revealed that recognition involves complex perceptional processes and is dependent on social experience. Using a series of systematically varied spot patterns, it was found that the monkeys generalize within a wide but well-defined range of stimuli. There was a clear-cut gender difference in alarm responses, with the males exerting a leading role both in onset and ceasing of terrestrial predator alarm. Both the socially experienced and inexperienced subjects responded with the species-specific avian alarm and flight reaction to fast moving patterns. Only the speed, not the shape, was relevant.

Animals↗