Exp Brain Res (2008) 186:131–141 DOI 10.1007/s00221-007-1216-5 123 RESEARCH ARTICLE Auditory-motor and cognitive aspects in area 8B of macaque monkey’s frontal cortex: a premotor ear–eye Weld (PEEF) C. Lucchetti · M. Lanzilotto · L. Bon Received: 15 June 2007 / Accepted: 6 November 2007 / Published online: 24 November 2007  Springer-Verlag 2007 Abstract In previous reports, we showed the involvement of area 8B neurons in both spontaneous ear and eye move- ment and in auditory information processing. Audition- related cells responded to complex environmental stimuli, but not to pure tones, and their activity changed during visual Wxation as a possible inhibitory expression of the engagement of attention. We observed auditory, auditory- motor and motor cells for both eye and ear movements. This Wnding suggests that area 8B may be involved in the integration of auditory input with ear and eye motor output. In this paper, we extended these previous studies by exam- ining area 8B activity in relation to auditive orienting behaviour, as well as the ocular orientation (i.e., visual Wxa- tion) studied previously. Visual Wxation led to inhibition of activity in auditory and auditory-motor cells, which sug- gests that attention may be involved in both, maintaining the eye position and reducing the response of these cell types. Accordingly, during a given task or natural behav- iour, spatial attention seems to aVect more than one sensori- motor channel simultaneously. These data add to our understanding of how the neural network, through a two- channel attentive process, accomplishes to switch between two eVectors, namely eyes and ears. Considering the func- tional, anatomical and cytoarchitectonic diVerences among the frontal eye Weld (FEF), the supplementary eye Weld (SEF) and area 8B, we propose to consider area 8B as a separate premotor ear–eye Weld (PEEF). Keywords Premotor cortex · 8B Auditory · Attention · Eye movement · Ear movement · Monkey Introduction In macaque monkeys, area 8B is located anterior to the ros- tral part of the dorsal agranular area six(Walker 1940). Anatomical investigations showed the presence of complex connections between dorsal prefrontal areas, including area 8B, and other cortical areas (Barbas and Mesulam 1981; Barbas and Pandya 1989; Barbas et al. 1999; Luppino et al. 2003). Moreover, area 8B sends projections to the deep lay- ers of the superior colliculus, pretectum and nucleus reticu- laris tegmentum ponti (NRTP) (Schmahmann and Pandya 1997; Fries 1984; Tanila et al. 1993). Quantitative studies have established the basis of inhibitory interactions between prefrontal areas nine and ten and inhibitory neu- rons in superior temporal cortices involved in auditory per- ception (Barbas et al. 2005), and these principles are likely to apply to areas 8B as well. Evidence of evoked eye and ear movements has been found in the frontal cortex, particularly in the frontal eye Weld (FEF area 8A), the supplementary eye Weld (SEF) and area 8B (Bruce et al. 1985; Schlag and Schlag-Rey 1987; Mitz and Godschalk 1989; Bon and Lucchetti 1992; Tehovnik and Lee 1993; Stepniewska et al. 1993; Bon and Lucchetti 1994; Schall 1991; Preuss et al. 1996; Tehovnik and Sommer 1997). Unit activity has been studied in areas 9, 8A, and 8B and in SEF in relation to both auditory stimuli and eye/ear motor control (Vaadia et al. 1986; Schlag and Schlag-Rey 1987; Bon and Lucchetti 1994; Russo and Bruce 1994; Schall 1991; Fuster et al. 2000; Bon and Lucchetti 2006). In this paper, we show the presence of auditory-motor and motor neurons in area 8B, and the eVect of the C. Lucchetti · M. Lanzilotto · L. Bon (&) Department of Biomedical Sciences Section of Physiology and Animal Facilities Centre Section of Policlinic, University of Modena and Reggio Emilia, Via Campi 287, 41100 Modena, Italy e-mail: bon.leopoldo@unimore.it; bonleo@unimo.it