?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Types+of+memory+or+attention+%3F+Impairments+after+lesions+of+the+hippocampus+and+limbic+ventral+tegmentum&rft.creator=Oades%2C+&rft.subject=Behavioral+Neuroscience&rft.subject=Behavioral+Biology&rft.subject=Psychobiology&rft.description=Introduction%3A+%0AAn+animal+with+an+unimpaired+reference+memory+can+distinguish+between+alternatives+that+belong+to+a+rewarded+set+and+those+that+are+always+unrewarded.+An+animal+with+an+unimpaired+working+memory+can+distinguish+beween+alternatives+where+it+has+been+rewarded+(e.g.+food+has+been+eaten%2C+but+not+replaced)+and+those+where+it+will+still+be+rewarded.%0AOlton+et+al.%2C+1979+proposed+that+fimbria-fornix+or+hippocampal+lesions+impairs+working+rather+than+reference+memory+in+a+radial+maze.+This+hypothesis+was+tested+for+rats+with+damage+to+the+hippocampus%2C+limbic+ventral+tegmentum+(VTA+A10+)+and+neocortex%2C+intact+and+operated+controls+on+a+16-hole-board+search+task.%0A%0AMethods%3A%0AFood-deprived+animals+searched+for+food+pellets+placed+consistently+in+4+holes+of+a+16-hole-board+(figure+1).+They+were+presented+with+11+sessions+of+10+trials%2Fsession.+There+were+five+groups+of+animals%2C+-+one+with+aspiration+lesions+of+the+hippocampus+and+overlying+neocortex%2C+one+with+damage+only+to+the+overlying+neocortex+and+sham-controls+that+went+through+the+procedure+but+the+brain+was+left+intact+(Oades+and+Isaacson%2C+1978)+-+VTA+damage+resulted+from+coagulation+with+a+stylet+in+a+sterotaxically+implanted+cannula+and+their+controls+received+the+cannula+alone.%0AWorking+memory+error+%3D+a+visit+to+a+correct+hole+that+has+just+been+visited%2C+and+thus+no+longer+contains+a+food+pellet.%0AReference+memory+error+%3D+visit+to+a+hole+that+is+never+baited.%0A%0AResults%3A+%0A1%2F+A+reference+and+a+working+memory+impairment+(in+terms+of+errors+made)+was+recorded+for+animals+with+hippocampal+or+with+VTA+damage.%0A2%2F+The+impairments+were+significant+by+session+3+and+the+differences+amounted+to+more+than+50%25+by+the+end+of+testing.%0A%0AConclusions%3A%0A.There+was+a+striking+similarity+between+the+performances+of+animals+with+damage+to+the+hippocampus+and+those+with+damage+to+the+VTA+(that+projects+to+the+lateral+septum%2C+entorhinal+cortex+and+dentate+gyrus.+The+different+results+obtained+by+Olton+in+the+radial+maze+may+be+explained+by+the+discrete+trial+testing+conducted+in+the+radial+maze+that+contrasts+with+the+multiple+choices+that+an+animal+makes+on+a+hole-board.+Further+in+the+current+study+training+occurred+exclusively+post-operatively%2C+while+in+the+radial+maze+animals+had+received+some+preoperative+training.%0ABoth+lesioned+and+control+animals+expressed+preferred+sequences+of+hole-visits.+The+preference+was+weaker+in+the+lesioned+animals+but+the+number+of+changes+of+preference+between+sessions+did+not+differ+between+groups.+Thus+it+is+argued+that+limbic+and+mesolimbic+DA+substrates+are+crucially+involved+in+attentive+mechanisms+important+to+adaptive+learning+and+the+impairment+is+not+merely+one+of+forming+and+using+memory.%0A&rft.publisher=Ankho+Int.+Inc.&rft.date=1981&rft.type=Journal+(Paginated)&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Fcogprints.org%2F1482%2F2%2Frat-brbull-81.pdf&rft.identifier=++Oades%2C+++(1981)+Types+of+memory+or+attention+%3F+Impairments+after+lesions+of+the+hippocampus+and+limbic+ventral+tegmentum.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F1482%2F