The Rams are in the bottom three, one point above bottom side Wigan, with just one league win all season.
“In the first half we looked as though we were paralysed with fear,” Pearson told BBC Radio Derby.
“We have a group which undoubtedly at the moment are not living up to the expectations externally, certainly not living up to the expectations internally and that’s my responsibility because I’m the manager,” added former Leicester City manager Pearson, who took over at the iPro Stadium in the summer.
“If we don’t get the basics out there and we don’t get the level of commitment to the game out there, it remains a very tough ask of us to get the performances which warrant points.
“Given what happened, we are exactly where we should be in the league. We got what we deserved and that’s the bottom line.”
Pearson continued: “I can’t keep hoping that players are going to bring their best games to the table week in week out, and then not do it, so I might have to start making changes.
“If that means introducing some of the younger players then so be it, but ultimately it’s about getting a team on the field that want to play for us, want to show the levels of commitment and are prepared to go whatever distance it takes to get the result.”
Bamba to the Rams?
Former Leeds United captain Sol Bamba has been training with Derby.