Differential impact of posterior lesions in the left and right hemisphere on visual category learning and generalization to contrast reversal

Comparison of coherence, amplitude, and eLORETA patterns during Transcendental Meditation and TM-Sidhi practice

“…These structures are associated with object recognition, face and body recognition, word recognition, memory encoding, and retrieval of objects and scenes (Grill-Spector et al, 2006;Joseph, 2001). Research suggests left-and right-hemisphere subsystems of object recognition (Marsolek, 1995;Marsolek and Hudson, 1999)-the left hemisphere encodes abstract-category representations, relying on analytical assessment of independent dimensions of the stimulus; the right hemisphere processes specific instances of a category based on a specific-holistic representation of object categories, where features are represented in combination rather than independently (Langguth et al, 2009). During TM-Sidhi practice, eLORETA sources in right-hemisphere areas responsible for specific-holistic representations support the description of sanyama as a process involving the simultaneous experience of specificity of the sutra and the wholeness of pure consciousness.…”

Peripheral vision and pattern recognition: A review

“…This suggests a neural locus for learning at a much later stage of visual processing compared with that for perceptual learning. Pattern category learning has been indeed found to display more complex effects of lateralization (Langguth, Jüttner, Landis, Regard, & Rentschler, 2009) and to be much less specific to the trained location in the visual field (Jüttner & Rentschler, 2008), as will be discussed in the following section.…”

Complementary deficits in perceptual classification in pure alexia and acquired prosopagnosia – New insights from two classic cases

“…Such patterns have a well-defined one-dimensional part structure in terms of bright and dark bars along their horizontal symmetry axis. In the past, they have been used in numerous studies on visual categorization both in normal observers (e.g., Kahana and Bennett, 1994;Rentschler, 1996, 2000) and patients (Langguth et al, 2009). For the current experiments, the modulation frequencies of the fundamental and its third harmonic were set to 2 c/deg and 6 c/deg, respectively.…”

“…The ability to perform a same/different discrimination based on such stimulus representations may be partially preserved in the case of impairment of either the abstract-category or the specific-exemplar subsystem. Indeed there is evidence for such a dual processing of Gabor patterns in classification learning by patients with unilateral posterior lesions (Langguth et al, 2009). Finally, in the Texture condition the presence of additional distractors in the stimulus display could be expected to further impede the instantiation process, thus adding to the difficulty of the discrimination task.…”