A Novel Method for Training Mice in Visuo-Tactile 3-D Object Discrimination and Recognition.

Different roles for M1 and M2 receptors within perirhinal cortex in object recognition and discrimination

Chemogenetic inactivation of the dorsal hippocampus and medial prefrontal cortex, individually and concurrently, impairs object recognition and spatial memory consolidation in female mice

There is an ongoing debate regarding the nature of memory deficits that occur in the early stages of mild cognitive impairment (MCI). MCI has been associated with atrophy to regions that process objects, namely perirhinal and lateral entorhinal cortices. However, it is currently unclear whether older adults with early MCI will show memory deficits that are specific to objects, or whether they will also show memory deficits for other stimulus classes, such as scenes. We tested 75 older adults using an object and scene recognition task with stimulus-specific interference (i.e., exposure to irrelevant object or scene stimuli). We found an interaction (P = 0.05) whereby scores on the Montreal Cognitive Assessment, a neuropsychological test with high sensitivity to MCI, shared a stronger relationship with object recognition than with scene recognition performance. Interestingly, this relationship was not modulated by the stimulus category of interfering items. To further explore these findings, we also tested an amnesic patient (DA) with known medial temporal lobe damage. Like older adults with early signs of MCI, DA showed poorer object recognition than scene recognition performance. Additionally, his performance was not modulated by the stimulus category of interfering material. By demonstrating that object memory is more predictive of cognitive decline than scene memory, these findings support the notion of perirhinal and lateral entorhinal cortex dysfunction in the early stages of MCI. © 2016 Wiley Periodicals, Inc.

The basal ganglia are known to receive inputs from widespread regions of the cerebral cortex, such as the frontal, parietal, and temporal lobes. Of these cortical areas, only the frontal lobe is thought to be the target of basal ganglia output. One of the cortical regions that is a source of input to the basal ganglia is area TE, in inferotemporal cortex. This cortical area is thought to be critically involved in the recognition and discrimination of visual objects. Using retrograde transneuronal transport of herpes simplex virus type 1, we have found that one of the output nuclei of the basal ganglia, the substantia nigra pars reticulata, projects via the thalamus to TE. Thus, TE is not only a source of input to the basal ganglia, but also is a target of basal ganglia output. This result implies that the output of the basal ganglia influences higher order aspects of visual processing. In addition, we propose that dysfunction of the basal ganglia loop with TE leads to alterations in visual perception, including visual hallucinations.

Recent research has found visual object memory can be stored as part of a larger scene representation rather than independently of scene context. The present study examined how spatial and nonspatial contextual information modulate visual object memory. Two experiments tested participants’ visual memory by using a change detection task in which a target object's orientation was either the same as it appeared during initial viewing or changed. In addition, we examined the effect of spatial and nonspatial contextual manipulations on change detection performance. The results revealed that visual object representations can be maintained reliably after viewing arrays of objects. Moreover, change detection performance was significantly higher when either spatial or nonspatial contextual information remained the same in the test image. We concluded that while processing complex visual stimuli such as object arrays, visual object memory can be stored as part of a comprehensive scene representation, and both spatial and nonspatial contextual changes modulate visual memory retrieval and comparison.

Object discrimination through active electrolocation: Shape recognition and the influence of electrical noise

Degraded transfer of memories between the visual hemifields in normal macaques revealed by a novel infrared eyetracking method without head fixation

As we move through our environment, we encounter familiar objects from various viewpoints. Despite the ensuing variability of the images projected onto the retina, we have seemingly little difficulty when it comes to recognizing objects we encounter. We can, however, see how the objects are oriented, suggesting that object recognition is to a certain degree dissociable from perception of other object “features” such as orientation. Changes in orientation of objects, particularly inversion, can also affect how we perceive the objects. A particularly illustrative example (shown in Figure ​Figure1)1) is that of the Thatcher illusion (Thompson, 1980), where the grotesque appearance of a face with its inverted eyes and mouth is “hidden” when the whole face is also inverted. The percept itself, therefore, is affected by the change in orientation. In addition, there are also subtle effects of viewpoint changes on object recognition itself. For example, identifying rotated objects is more difficult when they are briefly presented than when viewing time is unlimited (Lawson and Jolicoeur, 2003), and identifying a face is considerably more difficult the face has been inverted (Yin, 1969), as is discrimination between characters “b” and “d,” or “p” and “q” which requires (physical or mental) rotation of the characters to upright, before we can be certain which letter we are looking at (Corballis and McLaren, 1984). Figure 1 Unaltered and “thatcherized” version of Margaret Thatcher's face. The grotesque appearance of the face when its eyes and mouth are inverted is hidden by the inversion of the whole image. Rotating the pictures to upright makes discrimination ... These subtle, yet persistent, effects of viewpoint changes on perception and recognition arise as a consequence of how visual object processing is handled by the brain. Here, I discuss how neural mechanisms underlying visual processing give rise to perception and recognition which can be both viewpoint dependent and viewpoint invariant depending on the timing of those processes, as well as specific task demands or current “perceptual goals” of an individual. To do so, I will firstly explain how temporal dynamics of low-level visual processing may give rise to impaired recognition at short viewing latencies and suggest that this may also relate to effects of viewpoint changes on perceptual experience. I will then discuss how the perceptual goals of an individual determines whether recognition is accomplished in viewpoint invariant or dependent manner with a particular focus on cognitive operations thought to be subserved by ventral and dorsal visual streams, namely object recognition and mental rotation, respectively.

Memory for object location requires at least three processes: object recognition, object location, and object-location binding. Gender-related differences during childhood are still a matter of debate, especially concerning memory for object location, where females are expected to outperform males. Memory for object position is pivotal for spatial navigation and its investigation during childhood is crucial in order to understand the roots of gender-related differences in spatial orientation. Actually, environmental objects, namely landmarks, can be located using egocentric and/or allocentric frames of references, as well as using the spatial translation between them. Here, we investigated gender-related differences during childhood in object recognition and location whenever a shift between egocentric and allocentric frame of reference is required. Sixty-three boys and 44 girls (aged between four and ten years old) were asked to egocentrically learn a path on the Walking Corsi Test enriched with three landmarks. Then, children were asked to recognize (object recognition) the landmarks encountered along the path and locate them (object location) on an allocentric configuration of the spatial array. Girls outperformed boys in locating landmarks, whereas no difference occurred in landmark recognition. These results provide insights into the gender-related differences in location memory of landmarks, suggesting that females are better than males in the object location component well before the age of 13.

Three-month-old infants’ object recognition across changes in viewpoint using an operant learning procedure

Object tracking is the main task in the field of computer vision. This chapter proposes and compares a new method for recognition and tracking by using CamShift and color detection. All the presented algorithms were programmed with Python programming language supported by OpenCV libraries, and executed with a credit card–size computer board called Raspberry Pi with attached external camera. A camera mimics and uses real-time digital videos for object recognition and tracking. The chapter also proposes a color detection algorithm in very low light conditions is proposed for the enhancement of target tracking. Mean shift is a nonparametric feature-space analysis technique for locating the maxima of a density function. The CamShift algorithm is dependent on an adaptation of mean shift algorithm. Histogram equalization is a nonlinear technique for adjusting the contrast of an image using its histogram.

Long-term effects of neonatal damage to the hippocampal formation and amygdaloid complex on object discrimination and object recognition in rhesus monkeys (Macaca mulatta).

Artificial vision: needs, functioning, and testing of a retinal electronic prosthesis

Orientational information can replace the traditional edges as basic image features ("primitives") for object recognition. A comparison of five different orientation operators on 3 x 3 windows is carried out, and it is found that these operators have similar performance. A first attempt at object recognition searches for minimum root mean square deviation of orientation in a picture. This technique shows better object discrimination than the traditional normalized cross-correlation of grey-level images. Additionally the parameters of the Gaussian distribution of orientational correlation can be accurately predicted by a simple theoretical model. The orientational correlation technique shows difficulties in recognizing geometrically distorted and partially occluded objects. For this reason a very robust algorithm for the recognition of simple objects is developed, based only on orientationl information as image feature, and local polar coordinates for the model of the object. Practical examples taken under difficult, natural conditions illustrate the reliable performance of the proposed algorithm, and it becomes apparent that orientational information is indeed a powerful image primitive.

In robotic tasks, object recognition and discrimination can be realized according to their physical properties, such as color, shape, stiffness, and surface textures. However, these external properties may fail if they are similar or even identical. In this case, internal properties of the objects can be considered, for example, the center of mass. Center of mass is an important inherent physical property of objects; however, due to the difficulties in its determination, it has never been applied in object discrimination tasks. In this work, we present a tactile-based approach to explore the center of mass of rigid objects and apply it in robotic object discrimination tasks. This work comprises three aspects: (a) continuous estimation of the target object's geometric information, (b) exploration of the center of mass, and (c) object discrimination based on the center of mass features. Experimental results show that by following our proposed approach, the center of mass of experimental objects can be accurately estimated, and objects of identical external properties but different mass distributions can be successfully discriminated. Our approach is also robust against the textural properties and stiffness of experimental objects.