Changing central Pacific El Niños reduce stability of North American salmon survival rates.

Pacific salmon are a dominant component of the northeast Pacific ecosystem. Their status is of concern because salmon abundance is highly variable--including protected stocks, a recently closed fishery, and actively managed fisheries that provide substantial ecosystem services. Variable ocean conditions, such as the Pacific Decadal Oscillation (PDO), have influenced these fisheries, while diminished diversity of freshwater habitats have increased variability via the portfolio effect.

Unilateral damage to the right cerebral hemisphere disrupts the apprehension of whole faces and their component parts.

Although most cases of acquired prosopagnosia are accompanied by bilateral brain lesions, a number also arise following right unilateral lesions. The prevailing consensus is that right hemisphere damage disrupts the configural apprehension of faces, which in turn forces a reliance on part-based processing. Here we describe a patient who following right hemisphere damage is not only unable to apprehend the configural aspects of faces, but is also unable to apprehend their component parts when these are presented within a whole, upright face.

Galvanic vestibular stimulation speeds visual memory recall.

The experiments of Alessandro Volta were amongst the first to indicate that visuo-spatial function can be altered by stimulating the vestibular nerves with galvanic current. Until recently, the beneficial effects of the procedure were masked by the high levels of electrical current applied, which induced nystagmus-related gaze deviation and spatial disorientation. However, several neuropsychological studies have shown that much weaker, imperceptible currents that do not elicit unpleasant side-effects can help overcome visual loss after stroke.

Visual selective attention in Parkinson's disease: dissociation of exogenous and endogenous inhibition.

Impairment in the inhibitory mechanism of visual selective attention in patients with Parkinson's disease (PD) is controversial. The present study sought to understand disparate findings in a manner analogous to the relative preservation of exogenously evoked movement and impairment of endogenously evoked movement. The authors examined inhibition of return (i.

Improvement of a face perception deficit via subsensory galvanic vestibular stimulation.

The remediative effect of galvanic vestibular stimulation (GVS) was investigated in a patient who, following right hemisphere damage, is profoundly unable to recognize faces. We administered a two-alternative forced choice match-to-sample task in which the patient had to choose which of two faces matched a sample face presented directly above, while bipolar, transcutaneous current was applied to the left and right vestibular nerves at a level below the patient's sensory threshold. Performance improved beyond the chance-level observed prestimulation, and relied on reversing the electrode polarity across two separate blocks of trials, such that each mastoid received positive current for one block and then negative charge for the next.

Evidence for intact selective attention in Alzheimer's disease patients using a location priming task.

Researchers examining selective attentional mechanisms in patients with Alzheimer's disease (AD) often report impairment in patients' ability to inhibit irrelevant or distracting information. However, in many studies reporting such failures, researchers used tasks that require semantic processing, which a large body of literature documents to be disrupted in AD. The authors of this study used a spatial location-priming task that minimized semantic processing to examine the phenomena of negative priming and facilitative priming in 13 AD patients and 13 healthy older adults.

Conditional discrimination learning in patients with bilateral medial temporal lobe amnesia.

The ability of bilateral medial temporal lobe amnesic patients (MT; n=8) and normal participants (NC; n=8) to acquire a conditional discrimination in trace and delay eyeblink conditioning paradigms was investigated. Experiment 1 assessed trace conditional discrimination learning by using a light conditional stimulus (S+/S-) and tone conditioned stimulus (CS) separated by a 1-s trace. NCs responded differentially on S+ trials (mean percent conditioned responses=66) versus S- trials (30).

Aware and unaware perception in hemispatial neglect: evidence from a stem completion priming task.

The current study used the process dissociation procedure in conjunction with a stem-completion priming task to disentangle the influences of aware and unaware perception in patients with hemispatial neglect. One lateralized picture prime was presented simultaneously with a filler picture followed by a centrally presented word stem. In the inclusion condition participants were asked to complete the word stem with the previously presented picture name; in the exclusion task they were asked to complete the stem with the name of a picture other than the one previously presented.