Felice L. Bedford

Perceptual and cognitive spatial learning

Ss were taught novel mappings between visual space and motor space with either a variant on a prism adaptation paradigm (Experiments 1 and 2) or a nonperceptual cognitive task (Experiments 3 and 4). First, discrimination training specified that 1 visual location required a new pointing response but another location did not. This led to unusual generalization unlike typical generalization decrement. Second, training at 9 locations specified that 1 location required a new response but that the remaining 8 did not. This simple isolation mapping was unlearnable and instead a flat function fit through all of space. In contrast, for the cognitive paradigm, not only was isolation of one region of space easily learned, it was the preferred pattern of generalization. Implications for perceptual learning, as well as the qualitative distinctions between perceptual and cognitive learning, are discussed.

Constraints on perceptual learning: objects and dimensions

The article addresses two questions about perceptual learning: What are the circumstances which produce learning? What is the content of learning? For each question, a critical principle is suggested: (1) Objects are constrained to behave in certain ways. If a violation is detected, an internal malfunction is assumed and subsequently corrected. (2) Learning involves mappings between entire perceptual dimensions rather than associations between individual stimuli. The principles are applied to two phenomena: the classic adaptation to prism distorted vision and the more recent, but equally elusive, McCollough effect. The view suggests a new interpretation of the McCollough effect and accounts for findings difficult to account for in other interpretations including which stimuli can successfully lead to contingent after-effects, the outcome of correlation manipulations, and why the effect exists at all. In addition, the phenomenon is linked to prism adaptation, usually regarded as a distinct type of plasticity. In general, the view advanced is that the two principles help distinguish perceptual learning from other types of learning processes.

A perception theory in mind–body medicine: guided imagery and mindful meditation as cross-modal adaptation

A new theory of mind–body interaction in healing is proposed based on considerations from the field of perception. It is suggested that the combined effect of visual imagery and mindful meditation on physical healing is simply another example of cross-modal adaptation in perception, much like adaptation to prism-displaced vision. It is argued that psychological interventions produce a conflict between the perceptual modalities of the immune system and vision (or touch), which leads to change in the immune system in order to realign the modalities. It is argued that mind–body interactions do not exist because of higher-order cognitive thoughts or beliefs influencing the body, but instead result from ordinary interactions between lower-level perceptual modalities that function to detect when sensory systems have made an error. The theory helps explain why certain illnesses may be more amenable to mind–body interaction, such as autoimmune conditions in which a sensory system (the immune system) has made an error. It also renders sensible erroneous changes, such as those brought about by “faith healers,” as conflicts between modalities that are resolved in favor of the wrong modality. The present view provides one of very few psychological theories of how guided imagery and mindfulness meditation bring about positive physical change. Also discussed are issues of self versus non-self, pain, cancer, body schema, attention, consciousness, and, importantly, developing the concept that the immune system is a rightful perceptual modality. Recognizing mind–body healing as perceptual cross-modal adaptation implies that a century of cross-modal perception research is applicable to the immune system.

The McCollough effect: dissociating retinal from spatial coordinates.

Three experiments were conducted to dissociate the perceived orientation of a stimulus from its orientation on the retina while inducing the McCollough effect. In the first experiment, the typical contingency between color and retinal orientation was eliminated by having subjects tilt their head 90° for half of the induction trials while the stimuli remained the same. The only relation remaining was that between color and the perceived or spatial orientation, which led to only a small contingent aftereffect. In contrast, when the spatial contingency was eliminated in the second experiment, the aftereffect was as large as when both contingencies were present. Finally, a third experiment determined that part of the small spatial effect obtained in the first experiment could be traced to hidden higher order retinal contingencies. The study suggested that even under optimal conditions the McCollough effect is not concerned with real-world properties of objects or events. Implications for several classes of theories are discussed.

The Missing Sense Modality: The Immune System

The five senses were handed down by Aristotle. I argue that it has only taken two millennia to recognize that the immune system has been the hidden sensory modality. The immune system completes the range of operation allowing detection of meaningful entities at all distances, from very near to very far. It also withstands the often implicit criteria for being a sense modality. Finally, cross-modal interactions between the immune system and vision and other sense modalities should be possible, opening up new research directions.

False categories in cognition: the Not-The-Liver fallacy

This paper reports on an increasingly frequent error committed in cognition research that at best slows progress, and at worse leads to self-perpetuating false claims and misguided research. The error involves how we identify meaningful processes and categories on the basis of data. Examples are given from three areas of cognition: (1) memory, where the misconception has fueled the popular implicit/explicit categories, (2) perception, where the misconception is used to re-evaluate the classic what/where division, and (3) motor skills, where it is used to draw conclusions from patients with Huntingtons disease. Reasons for the prevalence of this error, how it relates to double dissociations, and what it suggests about scientific reasoning are offered.

Sephardic signature in haplogroup T mitochondrial DNA

A rare combination of mutations within mitochondrial DNA subhaplogroup T2e is identified as affiliated with Sephardic Jews, a group that has received relatively little attention. Four investigations were pursued: Search of the motif in 250 000 control region records across 8 databases, comparison of frequencies of T subhaplogroups (T1, T2b, T2c, T2e, T4, T*) across 11 diverse populations, creation of a phylogenic median-joining network from public T2e control region entries, and analysis of one Sephardic mitochondrial full genomic sequence with the motif. It was found that the rare motif belonged only to Sephardic descendents (Turkey, Bulgaria), to inhabitants of North American regions known for secret Spanish–Jewish colonization, or were consistent with Sephardic ancestry. The incidence of subhaplogroup T2e decreased from the Western Arabian Peninsula to Italy to Spain and into Western Europe. The ratio of sister subhaplogroups T2e to T2b was found to vary 40-fold across populations from a low in the British Isles to a high in Saudi Arabia with the ratio in Sephardim more similar to Saudi Arabia, Egypt, and Italy than to hosts Spain and Portugal. Coding region mutations of 2308G and 14499T may locate the Sephardic signature within T2e, but additional samples and reworking of current T2e phylogenetic branch structure is needed. The Sephardic Turkish community has a less pronounced founder effect than some Ashkenazi groups considered singly (eg, Polish), but other comparisons of interest await comparable averaging. Registries of signatures will benefit the study of populations with a large number of smaller-size founders.

Can a Space-Perception Conflict Be Solved with Three Sense Modalities?

A cross-modal conflict over location was resolved in an unexpected way. When vision and proprioception provide conflicting information, which modality should dominate is ambiguous. A visual – proprioceptive conflict was created with a prism and, to logically disambiguate the problem, auditory information was added that either agreed with vision (group 1), agreed with proprioception (group 2), or was absent (group 3). While a scarcity of research addresses the interaction of three modalities, I predicted error should be attributed to the modality in the minority. Instead, the opposite was found: adaptation consisted of a large change in arm proprioception and a small change affecting vision in group 2, and the reverse in group 1. Group 1 was not different than group 3. Findings suggested adaptation to separate two-way conflicts, possibly influenced by direction of attention, rather than a direct solution to a three-way modality problem.

Are long-term changes to perception explained by Pavlovian associations or perceptual learning theory?

Discrepancies and surprises lead to learning. But when will they lead to perceptual learning? Bedford (1995) argues that all changes in perception that result from experience must meet special requirements not needed for other more familiar types of learning. However, it has been suggested recently (Allan and Siegel, 1997b) that certain facts argue against the perceptual learning view, and for a Pavlovian conditioning view, of the McCollough Effect, a visual illusion that results from experience. Closer examination shows that this is not the case.

Clarifying Mitochondrial DNA Subclades of T2e from Mideast to Mexico

We report on two of the oldest mitochondrial DNA clusters in existence with Jewish affiliation. Both are in haplogroup T2e1. Four unrelated individuals from the Mexico mtDNA project were found to have the control region mutations that characterize a Sephardic signature previously reported (motif 16114T-16192T within T2e). Full genomic sequencing found the identical coding region mutations as Sephardic individuals which provides genetic evidence for founders of Northern Mexico that were both female and Sephardic Jewish. This is in contrast to a more common finding of European male, but local female founders and additionally lends biological support to anecdotes and historical reports of Crypto-Jewish founding of the Coahuila, Nuevo Leon, and Tamaulipas regions of Mexico and influx to Southern Texas, USA. The haplotype is nested in an old tree with mutations at positions 2308 and 15499, presently of uncertain geographic origin. The second cluster, a Bulgarian Sephardic founding lineage (9181G within T2e) previously reported, was found here in a population of largely Americans of European descent, but only among Jewish individuals. The non-synonymous mutation in ATPase 6 was found among both Ashkenazi and Sephardic Jews from diverse regions of Czech Republic, Lithuania, the Netherlands, Poland, and Romania. Full genomic sequencing found great coding region variability with several haplotypes and suggested a Near East origin at least 3000 years old. This predates the split between Jewish groups, but more recent admixture between Sephardim and Ashkenazim cannot be ruled out. Together the two Jewish-affiliated clusters account for all the genetic distance found in branch T2e1 and much of T2e. The findings suggest reexamination of the origins of mitochondrial DNA haplogroup T2e as Levantine or early back migration to the Near East. New subclades of T2e are identified.