Orientation specificity tends to be higher in cells in low-level visual processing areas (Felleman & Van Essen 1991, Zeki 1993). In addition, it has been reported that external feedback regarding the correctness of a subject’s responses (response feedback) is not necessary for VPL to occur (Fahle et al. 1995, Poggio et al. 1992). The featural specificity and lack of need for response feedback led some researchers to suggest that VPL occurs in the early visual system.