We used gratings and shapes defined by relative motion to study selectivity for static kinetic boundaries in macaque V4 neurons. Kinetic gratings were generated by random pixels moving in opposite directions in the neighboring bars, either parallel to the orientation of the boundary (parallel kinetic grating) or perpendicular to the boundary (orthogonal kinetic grating). Neurons were also teste...

In a typical scene with many different objects, attentional mechanisms are needed to select relevant objects for visual processing and control over behavior. To test the role of area V4 in the selection of objects based on non-spatial features, we recorded from V4 neurons in the monkey, using a visual search paradigm. A cue stimulus was presented at the center of gaze, followed by a blank delay...

Competition-based models of visual attention propose that perceptual ambiguity is resolved through inhibition, which is stronger when objects share a greater number of neural receptive fields (RFs). According to this theory, the misallocation of attention to a salient distractor--that is, the capture of attention--can be indexed in RF-scaled interference costs. We used this pattern to investiga...

Twenty-four slowly adapting type 1 (SA1) and 26 rapidly adapting (RA) cutaneous mechanoreceptive afferents in the rhesus monkey were studied with an array of independently controlled, punctate probes that covered an entire fingerpad. Each afferent had a receptive field (RF) on a single fingerpad and was studied at 73 skin sites (50 mm2). The entire array was lowered to 1.6 mm below the point of...

This research examined the effects of planning and executive functions on young children's (ages 3-to 5-years) strategies in changing scripts. Young children (N = 77) performed a script task (doll task), three executive function tasks (DCCS, red/blue task, and nine box task), a planning task, and a receptive vocabulary task. In the doll task, young children first enacted a "changing clothes" sc...

Infants preferentially discriminate between speech tokens that cross native category boundaries prior to acquiring a large receptive vocabulary, implying a major role for unsupervised distributional learning strategies in phoneme acquisition in the first year of life. Multiple sources of between-speaker variability contribute to children's language input and thus complicate the problem of distr...

The visual system uses information about the relative depth of contours and surfaces to link and segment elements of visual scenes. The integration of form and depth information was studied in areas V1 and V2 of the alert macaque. Neurons in area V2 used contextual depth information to integrate occluded contours, signal the presence of object boundaries, and segment surfaces: (1) Amodal contou...

Cortical sensory neurons are commonly characterized using the receptive field, the linear dependence of their response on the stimulus. In primary auditory cortex neurons can be characterized by their spectrotemporal receptive fields, the spectral and temporal features of a sound that linearly drive a neuron. However, receptive fields do not capture the fact that the response of a cortical neur...

We examined reciprocal associations between early maternal language use and children's language and cognitive development in seventy ethnically diverse, low-income families. Mother-child dyads were videotaped when children were aged 2;0 and 3;0. Video transcripts were analyzed for quantity and lexical diversity of maternal and child language. Child cognitive development was assessed at both age...

Top-down restoration mechanisms can enhance perception of degraded speech. Even in normal hearing, however, a large variability has been observed in how effectively individuals can benefit from these mechanisms. To investigate if this variability is partially caused by individuals' linguistic and cognitive skills, normal-hearing participants of varying ages were assessed for receptive vocabular...