Investigation of object-based attention in pigeons (Columba livia) and hill mynas (Gracula religiosa) using a spatial cueing task.

In previous research, pigeons and hill mynas that performed differently on an object permanence task were presumed to attend to objects in different ways (Plowright, Reid, & Kilian, 1998). In the current study, we conducted 4 experiments to investigate if the attention of hill mynas and pigeons is object-based and if there are species differences in their visual-attentional processes. In Experiment 1, pigeons were tested in a spatial cueing task requiring them to respond sequentially to a cue and a target that appeared at 1 of the 4 ends of two rectangles.

Pigeons discriminate shapes based on topological features.

The use of topological features in visual recognition has been demonstrated only in species with global-cue precedence. We investigated whether pigeons, with local-cue precedence, use topological features as cues for discriminating different shapes. The subjects in the topology group were required to discriminate stimuli based on whether the shapes contained one or no holes, whereas the subjects in the pseudocategory group were required to discriminate stimuli based on arbitrary categories.

Use of redundant sets of landmark information by humans (Homo sapiens) in a goal-searching task in an open field and on a computer screen.

Landmark-based goal-searching tasks that were similar to those for pigeons (Ushitani & Jitsumori, 2011) were provided to human participants to investigate whether they could learn and use multiple sources of spatial information that redundantly indicate the position of a hidden target in both an open field (Experiment 1) and on a computer screen (Experiments 2 and 3). During the training in each experiment, participants learned to locate a target in 1 of 25 objects arranged in a 5 × 5 grid, using two differently colored, arrow-shaped (Experiments 1 and 2) or asymmetrically shaped (Experiment 3) landmarks placed adjacent to the goal and pointing to the goal location. The absolute location and directions of the landmarks varied across trials, but the constant configuration of the goal and the landmarks enabled participants to find the goal using both global configural information and local vector information (pointing to the goal by each individual landmark).

Rapid visual processing of picture stimuli by pigeons in an RSVP (rapid serial visual presentation) task.

Three experiments that were carried out in series with 5 pigeons used novel training methods to investigate the rapid visual processing of picture stimuli by pigeons. On each trial, a sequence containing 1 of 2 bird pictures (the target) and nontarget bird pictures (the distractors) was presented. After the termination of the last item in the sequence, the pigeons were required to choose 1 of 2 colored squares corresponding to the target presented in the preceding sequence.

Accelerated behavioural development changes fine-scale search behaviour and spatial memory in honey bees (Apis mellifera L.).

Normally, worker honey bees (Apis mellifera) begin foraging when more than 2 weeks old as adults, but if individual bees or the colony is stressed, bees often begin foraging precociously. Here, we examined whether bees that accelerated their behavioural development to begin foraging precociously differed from normal-aged foragers in cognitive performance. We used a social manipulation to generate precocious foragers from small experimental colonies and tested their performance in a free-flight visual reversal learning task, and a test of spatial memory.

Infant monkeys' concept of animacy: the role of eyes and fluffiness.

Both human and nonhuman primates have been suggested to possess some essential knowledge about animate entities, but it remains unclear whether the concept of animacy is shared across species, which properties are used as an "animacy marker," and whether such ability is present at birth. We investigated infant Japanese monkeys' looking responses towards novel objects varying in both physical appearance and self-propelled motion, with the aim of depicting the role of eyes and fluffiness in the early recognition of animacy. Presented with an inanimate natural stone, three-month-old monkeys showed longer looking times at the stone's self-propelled motion than at its baseline still posture.

Flexible learning and use of multiple-landmark information by pigeons (Columba livia) in a touch screen-based goal searching task.

Three touch screen-based experiments were conducted to investigate whether pigeons would learn to use configural information about a goal's location in relation to a multiple-landmark array. In Experiment 1, 4 pigeons (Columba livia) were trained to peck a computer monitor at a location that constituted the third vertex of a hypothetical triangle defined by 2 different landmarks. The landmarks appeared in 3 orientations during the training, and the pigeons' goal-searching ability easily transferred to the landmarks presented in 3 novel orientations.

The learning of basic-level categories by pigeons: the prototype effect, attention, and effects of categorization.

Pigeons were trained to classify composite faces of two categories created by mimicking the structure of basic-level categories, with each face consisting of an item-specific component and a common component diagnostic for its category. Classification accuracy increased as the proportion of common components increased, regardless of familiar and novel item-specific components, with the best discrimination occurring at untrained original faces used as the common components. A no-categorization control condition suggested that categorization gives rise to equivalence for item-specific components and distinctiveness for degrees of prototypicality.

A slowing effect on visual search by advance information in pigeons (Columba livia): a comparison with humans (Homo sapiens).

A comparative study was conducted to investigate whether the search for a target letter was facilitated when the target and prime (preceding stimulus) letters were identical. Pigeons (Section 2) and human participants (Section 3) were first trained to search for "A" among "Y"s and "E" among "D"s in a condition in which a square shape appeared as the prime (Neutral condition). In subsequent testing, a prime was identical either to the corresponding target (Target-priming condition) or to the distractor (Distractor-priming condition).

Object-based attention in chimpanzees (Pan troglodytes).

We conducted three experiments to investigate how object-based components contribute to the attentional processes of chimpanzees and to examine how such processes operate with regard to perceptually structured objects. In Experiment 1, chimpanzees responded to a spatial cueing task that required them to touch a target appearing at either end of two parallel rectangles. We compared the time involved in shifting attention (cost of attentional shift) when the locations of targets were cued and non cued.

Performance of pigeons (Columba livia) on maze problems presented on the LCD screen: in search for preplanning ability in an avian species.

The authors examined how pigeons (Columba livia) perform on 2-dimensional maze tasks on the LCD monitor and whether the pigeons preplan the solution before starting to solve the maze. After training 4 pigeons to move a red square (the target) to a blue square (the goal) by pecking, the authors exposed them to a variety of detour tasks having lines as a barrier. A preview phase was introduced, during which the pigeons were not allowed to peck at the monitor.

Perception of the standard and the reversed Müller-Lyer figures in pigeons (Columba livia) and humans (Homo sapiens).

The authors compared perception of the standard and reversed Müller-Lyer figures between pigeons (Columbia livia) and humans (Homo sapiens). In Experiment 1, pigeons learned to classify 6 lengths of target lines into "long" and "short" categories by pecking 2 keys on the monitor, ignoring the 2 brackets so placed that they would not induce an illusion. In the test that followed, all 3 birds chose the "long" key more frequently for the standard Müller-Lyer figures with inward-pointing brackets (><) than for the figures with outward-pointing brackets (<>).

Pigeons do not perceptually complete partly occluded photos of food: an ecological approach to the "pigeon problem".

Humans routinely complete partly occluded objects to recognize the whole objects. However, a number of studies using geometrical figures and even conspecific images have shown that pigeons fail to do so. In the present study, we tested whether pigeons complete partially occluded objects in a situation simulating a natural feeding context.

Better living by not completing: a wonderful peculiarity of pigeon vision?

Whereas many non-human species have been demonstrated to visually complete partly occluded figures, pigeons have been repeatedly failed to do so. We asked whether this failure reflected the pigeons' lack of perceptual process for completion or their decision among completed and non-completed figures. Four pigeons searched for a red lozenge target having one of its four contours punched in a rectangular edge out among three intact lozenges.